ovalbumin and Autoimmune-Diseases

Induction of peripheral immunological tolerance by mucosal administration of selected antigens (Ags) ('oral tolerance') is an attractive, yet medically little developed, approach to prevent or treat selected autoimmune or allergic disorders. A highly effective way to maximize oral tolerance induction for immunotherapeutic purposes is to administer the relevant Ag together with, and preferably linked to the non-toxic B subunit protein of cholera toxin (CTB). Oral, nasal or sublingual administration of such Ag/CTB conjugates or gene fusion proteins have been found to induce tolerance with superior efficiency compared with administration of Ag alone, including the suppression of various autoimmune disorders and allergies in animal models. In a proof-of-concept clinical trial in patients with Behcet's disease, this was extended with highly promising results to prevent relapse of autoimmune uveitis. Tolerization by mucosal Ag/CTB administration results in a strong increase in Ag-specific regulatory CD4(+) T cells, apparently via two separate pathways: one using B cells as APCs and leading to a strong expansion of Foxp3(+) Treg cells which can both suppress and mediate apoptotic depletion of effector T cells, and one being B cell-independent and associated with development of Foxp3(-) regulatory T cells that express membrane latency-associated peptide and transforming growth factor (TGF-beta) and/or IL-10. The ability of CTB to dramatically increase mucosal Ag uptake and presentation by different APCs through binding to GM1 ganglioside (which makes most B cells effective APCs irrespective of their Ag specificity), together with CTB-mediated stimulation of TGF-beta and IL-10 production and inhibition of IL-6 formation may explain the dramatic potentiation of oral tolerance by mucosal Ags presented with CTB.

Topics: Adjuvants, Immunologic; Animals; Antigen-Presenting Cells; Autoimmune Diseases; Cholera Toxin; Cytokines; Humans; Immune Tolerance; Immunity, Mucosal; Immunotherapy; Ovalbumin; T-Lymphocytes, Regulatory

The immune-privileged status of the anterior chamber of the eye is altered in experimentally induced intraocular inflammation and in the pigment dispersion syndrome of DBA/2J mice. However, the eye has developed multiple mechanisms to maintain ocular immune privilege even in the presence of intraocular inflammation.

Topics: Animals; Anterior Chamber; Autoimmune Diseases; Eye; Humans; Immune Tolerance; Mice; Ovalbumin; Transforming Growth Factor beta; Uveitis

Mucosal immune response to an antigen leads to a state of attenuated systemic response to the same antigen, known as mucosal or oral tolerance. Thus, autoantigen administration via mucosal routes could be useful in the prevention of autoimmune diseases. Although in various models of autoimmune disease it is often effective, in some cases it is ineffective and in other cases even harmful. In these cases it is likely that, concomitantly with tolerance, a productive immune response is induced that exacerbates autoimmunity. Recent evidence suggests that induction of cytotoxic T lymphocytes capable of destroying pancreatic beta cells may be an unavoidable consequence of mucosal administration of pancreatic beta-cell associated autoantigen. To improve the safety and efficacy of mucosal tolerance induction in the prevention of type 1 diabetes, further means to control the induction of cytotoxic T lymphocytes and other potentially tissue-destructive immune effectors may be required.

Topics: Administration, Intranasal; Administration, Oral; Animals; Autoantigens; Autoimmune Diseases; Desensitization, Immunologic; Diabetes Mellitus, Type 1; Digestive System; Humans; Immune Tolerance; Immunization; Islets of Langerhans; Lymphoid Tissue; Mice; Mice, Inbred NOD; Mice, Transgenic; Mucous Membrane; Ovalbumin; Rats; Safety; T-Lymphocytes, Cytotoxic

Oral administration of antigen is known to induce a state of specific immunological unresponsiveness to a subsequent challenge with the same antigen. Based on this, oral delivery of autoantigens has been applied as a possible strategy for the treatment of human autoimmune diseases like rheumatoid arthritis and multiple sclerosis. The precise mechanisms involved in the induction of oral tolerance are yet to be clearly defined. In an attempt to address this issue, we have generated several lines of transgenic mice using ovalbumin (OVA) as the model antigen. Our studies have shown that a cytotoxic T lymphocyte response could be induced by oral administration of antigen and that this could lead to the onset of autoimmune disease. These findings suggest caution should be applied when oral administration of antigen is used to treat human autoimmune diseases.

Topics: Administration, Oral; Animals; Antigens; Autoimmune Diseases; Humans; Immune Tolerance; Mice; Mice, Transgenic; Ovalbumin; T-Lymphocytes, Cytotoxic

Autoimmune diseases affect over 4% of the world's population. Treatments are generally palliative or use broad spectrum immunosuppressants to reduce symptoms and disease progression. In some diseases, antibodies generated to a single autoantigen are the major cause of pathogenic inflammation, suggesting that treatments to induce tolerance to the autoantigen could be therapeutic. Here we report the development of hybrid nanoparticles (NPs) that induce tolerance in both T cells and B cells. The NPs comprise a lipid monolayer encapsulating a PLGA core loaded with rapamycin that promotes development of regulatory T cells (Tregs). The lipid monolayer displays the protein antigen and a ligand of the B cell inhibitory co-receptor CD22 (CD22L) that act together to suppress activation of B cells recognizing the antigen. We demonstrate that the hybrid NPs decorated with ovalbumin (OVA) elicit tolerance to OVA in naı̈ve mice, as judged by low OVA-specific antibody titers after the challenge. In the K/BxN mouse model of rheumatoid arthritis caused by B and T cell-dependent responses to the self-antigen glucose-6-phosphate-isomerase (GPI), we show that GPI hybrid NPs delay development of disease, with some treated mice remaining arthritis-free for 300 days. We provide evidence that the mechanism of rheumatoid arthritis suppression involves induction of B cell tolerance, as measured by low anti-GPI antibodies and decreased plasma cell populations, and T cell tolerance, as measured by increased Tregs. The results show the potential of this versatile NP platform for inducing immune tolerance to a self-antigen and suppressing autoimmune disease.

Topics: Animals; Arthritis, Rheumatoid; Autoantigens; Autoimmune Diseases; Immune Tolerance; Lipids; Mice; Nanoparticles; Ovalbumin; Polylactic Acid-Polyglycolic Acid Copolymer

Topics: Animals; Antigens; Autoimmune Diseases; Cystitis; Cystitis, Interstitial; Cytokines; Disease Models, Animal; Gene Expression Regulation; Mice; Mice, Transgenic; Ovalbumin; Pelvic Pain; Urinary Bladder; Urination Disorders; Urothelium

Autoimmune diseases are caused by adaptive immune responses to self-antigens. The development of antigen-specific therapies that suppress disease-related, but not unrelated immune responses in general, is an important goal of biomedical research. We have previously shown that delivery of myelin peptides to liver sinusoidal endothelial cells (LSECs) using LSEC-targeting nanoparticles provides effective protection from CD4 T-cell-driven autoimmune encephalomyelitis. Here, we investigated whether this methodology might also serve antigen-specific treatment of a CD8 T-cell-driven autoimmune disease. As a model for CD8 T-cell-mediated autoimmunity, we used OT-1 T-cell-driven cholangitis in K14-OVAp mice expressing the cognate MHC I-restricted SIINFEKL peptide in cholangiocytes. To study whether peptide delivery to LSECs could modulate cholangitis, SIINFEKL peptide-conjugated nanoparticles were administered intravenously one day before transfer of OT-1 T cells; five days after cell transfer, liver pathology and hepatic infiltrates were analysed. SIINFEKL peptide-conjugated nanoparticles were rapidly taken up by LSECs in vivo, which effectively cross-presented the delivered peptide on MHC I molecules. Intriguingly, K14-OVAp mice receiving SIINFEKL-loaded nanoparticles manifested significantly reduced liver damage compared with vehicle-treated K14-OVAp mice. Mechanistically, treatment with LSEC-targeting SIINFEKL-loaded nanoparticles significantly reduced the number of liver-infiltrating OT-1 T cells, which up-regulated expression of the co-inhibitory receptor PD-1 and down-regulated cytotoxic effector function and inflammatory cytokine production. These findings show that tolerogenic LSECs can effectively internalize circulating nanoparticles and cross-present nanoparticle-bound peptides on MHC I molecules. Therefore, nanoparticle-mediated autoantigen peptide delivery to LSECs might serve the antigen-specific treatment of CD8 T-cell-driven autoimmune disease.

Topics: Animals; Autoantigens; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Cells, Cultured; Cholangitis; Cross-Priming; Cytotoxicity, Immunologic; Disease Models, Animal; Endothelial Cells; Humans; Immunosuppression Therapy; Immunotherapy; Liver; Magnetic Iron Oxide Nanoparticles; Mice; Mice, Transgenic; Ovalbumin; Peptide Fragments; Programmed Cell Death 1 Receptor; T-Lymphocytes, Regulatory

Age-related thymic atrophy results in reduced output of naïve conventional T (Tcon) cells. However, its impact on regulatory T (Treg) cells is insufficiently understood. Given evidence that thymic Treg (tTreg) cell generation is enhanced in the aged, atrophy thymus and that the aged periphery accumulates peripheral Treg (pTreg) cells, we asked why these Treg cells are unable to effectively attenuate increased autoreactivity-induced chronic inflammation in the elderly. We designed a mock-self-antigen chimera mouse model, in which membrane-bound ovalbumin (mOVA) transgenic mice, bearing a FoxN1-floxed gene for induction of conditional thymic atrophy, received OVA-specific (OT-II) T-cell receptor (TCR) transgenic progenitor cells. The chimeric mice with thymic atrophy exhibited a significant decrease in OVA-specific tTreg and pTreg cells but not polyclonal (pan)-Treg cells. These OVA-specific pTreg cells were significantly less able to suppress OVA-specific stimulation-induced proliferation in vitro and exhibited lower FoxP3 expression. Additionally, we conducted preliminary TCR repertoire diversity sequencing for Treg cells among recent thymic emigrants (RTEs) from Rag

Topics: Aged; Aging; Animals; Atrophy; Autoantigens; Autoimmune Diseases; Clonal Selection, Antigen-Mediated; Clone Cells; Humans; Immunomodulation; Inflammation; Mice; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell; T-Cell Antigen Receptor Specificity; T-Lymphocytes, Regulatory; Thymus Gland; Transplantation Chimera

Apoptotic cells mediate the development of tolerogenic dendritic cells (DC) and thus facilitate induction and maintenance of peripheral tolerance. Following the identification of the evolutionary conserved annexin core domain (Anx) as a specific signal on apoptotic cells which antagonises Toll-like receptor (TLR) signalling, we examined whether the tolerogenic capacity of Anx can be exploited to downregulate antigen-specific immune responses. The treatment of bone marrow-derived dendritic cells (BMDC) with particles harbouring Anx as well as the model antigen ovalbumin (OVA) attenuated the response of OVA-specific OT-II T cells. The co-culture of Anx-particle-treated DC and T cells resulted in an anergy-like phenotype characterized by reduced proliferation and cytokine secretion. Here we demonstrate that the anti-inflammatory effects of Anx which are mediated through DC can be used as a tool to generate a particle-based antigen delivery system that promotes antigen-specific immunosuppression. Such Anx-particles may be a new therapeutic approach for the treatment of autoimmune diseases.

Topics: Animals; Annexins; Antigens; Apoptosis; Autoimmune Diseases; Cell Proliferation; Cells, Cultured; Coculture Techniques; Dendritic Cells; Drug Delivery Systems; Humans; Immune Tolerance; Mice; Microspheres; Ovalbumin; Primary Cell Culture; Protein Domains; T-Lymphocytes

Topics: Animals; Autoimmune Diseases; Cell Survival; Female; Inflammation; Interleukin-17; Interleukin-1beta; Interleukin-2; Interleukin-23; Intraepithelial Lymphocytes; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Neutralization Tests; Nuclear Receptor Subfamily 1, Group F, Member 3; Ovalbumin; Receptors, Antigen, T-Cell, gamma-delta; Spleen; STAT5 Transcription Factor; Th17 Cells

Immune homeostasis in peripheral tissues is, to a large degree, maintained by the differentiation and action of regulatory T cells (Treg) specific for tissue Ags. Using a novel mouse model, we have studied the differentiation of naive CD4

Topics: Animals; Autoimmune Diseases; Cell Differentiation; Disease Models, Animal; Forkhead Transcription Factors; Humans; Lymphocyte Activation; Mice; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell; Signal Transduction; Sirolimus; Skin; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; TOR Serine-Threonine Kinases

Combining autoantigens with immune-modulating drugs has emerged as an attractive approach to selectively reinstate tolerance in autoimmune diseases. The disparate properties of autoantigens and small-molecule immunosuppressants commonly used to treat autoimmune diseases can confound efforts to co-deliver these therapies. However, both components may be co-delivered with adjuvants which have been successful in delivering antigens to immune cells. We evaluated several common adjuvants as vehicles to co-deliver a model antigen and immunosuppressant, ovalbumin (OVA) and dexamethasone (DEX), respectively. Formulations were developed, and the release of DEX from adjuvants was investigated. Next, the effect of adjuvant, DEX, and OVA was tested in vitro using a DC line. A MF59-analog (MF59a) formulation was advanced to more sophisticated co-culture studies using OVA-primed bone marrow-derived dendritic cells and splenocytes or T-cells from OT-II mice. Most of these studies indicated MF59a-based antigen-specific immunotherapies could diminish the markers of inflammation associated with OVA recognition. We rationalized MF59a co-delivery of antigen and drug could reduce the risk of side effects typically associated with these drugs and reinstate immune tolerance, thus prompting continued investigation of emulsion adjuvants as delivery vehicles for antigen-specific immunotherapy of autoimmune diseases.

Topics: Adjuvants, Immunologic; Adjuvants, Pharmaceutic; Animals; Autoantigens; Autoimmune Diseases; Bone Marrow; Coculture Techniques; Dendritic Cells; Dexamethasone; Emulsions; Immune Tolerance; Immunotherapy; Inflammation; Mice; Mice, Inbred C57BL; Ovalbumin; T-Lymphocytes

Increasing evidence suggests a role of CD8 T cells in autoimmune demyelinating CNS disease, which, however, is still controversially discussed. Mice, which express ovalbumin (OVA) as cytosolic self-antigen in oligodendrocytes (ODC-OVA mice), respond to CNS infection induced by OVA-expressing attenuated Listeria with CD8 T cell-mediated inflammatory demyelination. This model is suitable to decipher the contribution of CD8 T cells and the pathogen in autoimmune CNS disease. Here, we show that both antigen and pathogen are required in the CNS for disease induction, though not in a physically linked fashion. Intracerebral challenge with combined toll like receptor (TLR) TLR2 and TLR9 as well as TLR7 and TLR9 agonists substituted for the bacterial stimulus, but not with individual TLR agonists (TLR2, TLR3,TLR5,TLR7, TLR9). Furthermore, MyD88 inactivation rendered ODC-OVA mice resistant to disease induction. Collectively, CD8 T cell-mediated destruction of oligodendrocytes is activated if (i) an antigen shared with an infectious agent is provided in the CNS microenvironment and (ii) innate immune signals inform the CNS microenvironment that pathogen removal warrants an immune attack by CD8 T cells, even at the expense of locally restricted demyelination.

Topics: Animals; Antigens; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Cells, Cultured; Central Nervous System; Demyelinating Diseases; Listeria monocytogenes; Listeriosis; Mice, Inbred C57BL; Myeloid Differentiation Factor 88; Oligodendroglia; Ovalbumin; Signal Transduction; Toll-Like Receptors

Altered Toll-like receptor (TLR)4 activation has been identified in several chronic pain conditions but has not been well studied in interstitial cystitis/bladder pain syndrome (IC/BPS). Our previously published human studies indicated that patients with IC/BPS present altered systemic TLR4-mediated inflammatory responses, which were significantly correlated with reported pain severity. In the present study, we sought to determine whether altered TLR4 activation plays a role in pelvic/bladder pain seen in patients with IC/BPS using our validated IC/BPS-like transgenic autoimmune cystitis model (URO-OVA). URO-OVA mice developed responses consistent with pelvic and bladder pain after cystitis induction, which was associated with increased splenocyte production of TLR4-mediated proinflammatory cytokines IL-1β, IL-6, and TNF-α. Increased spinal expression of mRNAs for proinflammatory cytokines IL-6 and TNF-α, glial activation markers CD11b and glial fibrillary acidic protein, and endogenous TLR4 ligand high mobility group box 1 was also observed after cystitis induction. Compared with URO-OVA mice, TLR4-deficient URO-OVA mice developed significantly reduced nociceptive responses, although similar bladder inflammation and voiding dysfunction, after cystitis induction. Intravenous administration of TAK-242 (a TLR4-selective antagonist) significantly attenuated nociceptive responses in cystitis-induced URO-OVA mice, which was associated with reduced splenocyte production of TLR4-mediated IL-1β, IL-6, and TNF-α as well as reduced spinal expression of mRNAs for IL-6, TNF-α, CD11b, glial fibrillary acidic protein, and high mobility group box 1. Our results indicate that altered TLR4 activation plays a critical role in bladder nociception independent of inflammation and voiding dysfunction in the URO-OVA model, providing a potential mechanistic insight and therapeutic target for IC/BPS pain.

Topics: Analgesics; Animals; Autoimmune Diseases; Cells, Cultured; Cystitis, Interstitial; Cytokines; Disease Models, Animal; Inflammation Mediators; Mice, Inbred C57BL; Mice, Knockout; Nociceptive Pain; Ovalbumin; Pain Threshold; Signal Transduction; Spine; Spleen; Sulfonamides; Toll-Like Receptor 4; Urinary Bladder; Urodynamics

While autoimmune T cells are present in most individuals, only a minority of the population suffers from an autoimmune disease. To better appreciate the limits of T cell tolerance, we carried out experiments to determine how many autoimmune T cells are required to initiate an experimental autoimmune disease. Variable numbers of autoimmune OT-I T cells were transferred into RIP-OVA mice, which were injected with antigen-loaded DCs in a single footpad; this restricted T cell priming to a few OT-I T cells that are present in the draining popliteal lymph node. Using selective plane illumination microscopy (SPIM) we counted the number of OT-I T cells present in the popliteal lymph node at the time of priming. Analysis of our data suggests that a single autoimmune T cell cannot induce an experimental autoimmune disease, but a "quorum" of 2-5 autoimmune T cells clearly has this capacity.

Topics: Adoptive Transfer; Animals; Antigen Presentation; Autoimmune Diseases; Autoimmunity; CD8-Positive T-Lymphocytes; Dendritic Cells; Diabetes Mellitus, Experimental; Disease Models, Animal; Immune Tolerance; Lymph Nodes; Mice; Mice, Transgenic; Ovalbumin

The nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR readily induced NRF2-sensitive heme oxygenase 1 (HO-1) mRNA and protein in LPS-activated DC. HO-1 enhanced STAT3 phosphorylation, which enriched to Il12b and Il23a loci and negatively regulated their transcription. These findings demonstrate the underlying mechanism through which a nutritional can interfere with the immune response. CUR silences IL-23/Th17-mediated pathology by enhancing HO-1/STAT3 interaction in DC.

Topics: Animals; Autoimmune Diseases; Curcumin; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Heme Oxygenase-1; Immunity, Cellular; Inflammation; Interleukin-23; Membrane Proteins; Mice; Ovalbumin; Phosphorylation; STAT3 Transcription Factor; Th17 Cells; Th2 Cells

The Kv1.3 channel-acting scorpion toxins usually adopt the conserved anti-parallel β-sheet domain as the binding interface, but it remains challenging to discover some highly selective Kv1.3 channel-acting toxins. In this work, we investigated the pharmacological profile of the Kv1.3 channel-acting BmKTX-D33H, a structural analogue of the BmKTX scorpion toxin. Interestingly, BmKTX-D33H, with its conserved anti-parallel β-sheet domain as a Kv1.3 channel-interacting interface, exhibited more than 1000-fold selectivity towards the Kv1.3 channel as compared to other K⁺ channels (including Kv1.1, Kv1.2, Kv1.7, Kv11.1, KCa2.2, KCa2.3, and KCa3.1). As expected, BmKTX-D33H was found to inhibit the cytokine production and proliferation of both Jurkat cells and human T cells in vitro. It also significantly improved the delayed-type hypersensitivity (DTH) responses, an autoreactive T cell-mediated inflammation in rats. Amino acid sequence alignment and structural analysis strongly suggest that the "evolutionary" Gly11 residue of BmKTX-D33H interacts with the turret domain of Kv1 channels; it appears to be a pivotal amino acid residue with regard to the selectivity of BmKTX-D33H towards the Kv1.3 channel (in comparison with the highly homologous scorpion toxins). Together, our data indicate that BmKTX-D33H is a Kv1.3 channel-specific blocker. Finally, the remarkable selectivity of BmKTX-D33H highlights the great potential of evolutionary-guided peptide drug design in future studies.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; CD3 Complex; Cell Proliferation; Cells, Cultured; Cytokines; Female; HEK293 Cells; Humans; Hypersensitivity, Delayed; Immunologic Factors; Jurkat Cells; Kv1.3 Potassium Channel; Ovalbumin; Potassium Channel Blockers; Rats, Inbred Lew; Scorpion Venoms; Scorpions; Sequence Alignment; T-Lymphocytes

Rheumatoid arthritis (RA) is an autoimmune connective tissue disease, associated with the presence of anti-citrullinated protein antibodies (ACPA). These antibodies have been found in approximately 70% of patients suffering from RA and they are currently used for diagnosis of RA. Although they exhibit an absolute need for citrulline for antibody reactivity, no precise cognate antigen for these antibodies has been determined. In this study, we analyzed the reactivity of ACPA to various citrullinated peptides by modified enzyme-linked immunosorbent assays, in order to determine the dependency of specific amino acids for antibody reactivity. A non-human protein (ovalbumin) and antigens directly related to RA were used as templates for synthesis of non-modified and citrullinated peptides, becoming potential target epitopes. Mainly peptides containing a Cit-Gly motif were recognized by ACPAs, while no particular amino acids N-terminal of citrulline were found to be essential for antibody reactivity. Moreover, ACPA reactivity was not restricted to antigens known to be associated with ACPA-positive RA alone, but also to proteins without relation to RA, primarily illustrating that any protein in theory can be turned into an RA autoantigen, by introducing Cit-Gly motifs. Knowledge about the interaction between ACPAs and their citrullinated targets is important for understanding autoimmune ACPA responses in RA, which are known to contribute to the pathophysiology.

Topics: Amino Acid Motifs; Arthritis, Rheumatoid; Autoantibodies; Autoantigens; Autoimmune Diseases; Citrulline; Epitopes; Humans; Ovalbumin; Peptides

Primary biliary cirrhosis (PBC) is a progressive autoimmune liver disease with a long natural history. The pathogenesis of PBC is thought to be orchestrated by Th1 and/or Th17. In this study, we investigated the role of CD4

Topics: Animals; Autoimmune Diseases; Cholangitis; Dependovirus; Disease Models, Animal; Fatty Acids, Monounsaturated; Female; Fibrosis; Hepatitis; Interferon-gamma; Interleukin-4; Interleukins; Liver; Mice, Inbred C57BL; Ovalbumin; Precision Medicine; Th1 Cells

Bladder inflammation frequently causes cystitis pain and lower urinary tract dysfunction (LUTD) such as urinary frequency and urgency. Although mast cells have been identified to play a critical role in bladder inflammation and pain, the role of mast cells in cystitis-associated LUTD has not been demonstrated. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic and debilitating inflammatory condition of the urinary bladder characterized by the hallmark symptoms of pelvic pain and LUTD. In this study we investigated the role of mast cells in LUTD using a transgenic autoimmune cystitis model (URO-OVA) that reproduces many clinical correlates of IC/BPS. URO-OVA mice express the membrane form of the model antigen ovalbumin (OVA) as a self-antigen on the urothelium and develop bladder inflammation upon introduction of OVA-specific T cells. To investigate the role of mast cells, we crossed URO-OVA mice with mast cell-deficient KitW-sh mice to generate URO-OVA/KitW-sh mice that retained urothelial OVA expression but lacked endogenous mast cells. We compared URO-OVA mice with URO-OVA/KitW-sh mice with and without mast cell reconstitution in response to cystitis induction. URO-OVA mice developed profound bladder inflammation with increased mast cell counts and LUTD, including increased total number of voids, decreased mean volume voided per micturition, and decreased maximum volume voided per micturition, after cystitis induction. In contrast, similarly cystitis-induced URO-OVA/KitW-sh mice developed reduced bladder inflammation with no mast cells and LUTD detected. However, after mast cell reconstitution URO-OVA/KitW-sh mice restored the ability to develop bladder inflammation and LUTD following cystitis induction. We further treated URO-OVA mice with cromolyn, a mast cell membrane stabilizer, and found that cromolyn treatment reversed bladder inflammation and LUTD in the animal model. Our results provide direct evidence for the role of mast cells in cystitis-associated LUTD, supporting the use of mast cell inhibitors for treatment of certain forms of IC/BPS.

Topics: Animals; Autoimmune Diseases; Behavior, Animal; CD8-Positive T-Lymphocytes; Cells, Cultured; Cromolyn Sodium; Cystitis, Interstitial; Cytokines; Disease Models, Animal; Mast Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Pelvic Pain; Proto-Oncogene Proteins c-kit; RNA, Messenger; Urinary Bladder

Self/non-self discrimination characterizes immunity and allows responses against pathogens but not self-antigens. Understanding the principles that govern this process is essential for designing autoimmunity treatments. p21 is thought to attenuate autoreactivity by limiting T cell expansion. Here, we provide direct evidence for a p21 role in controlling autoimmune T cell autoreactivity without affecting normal T cell responses. We studied C57BL/6, C57BL/6/lpr and MRL/lpr mice overexpressing p21 in T cells, and showed reduced autoreactivity and lymphadenopathy in C57BL/6/lpr, and reduced mortality in MRL/lpr mice. p21 inhibited effector/memory CD4(+) CD8(+) and CD4(-)CD8(-) lpr T cell accumulation without altering defective lpr apoptosis. This was mediated by a previously non-described p21 function in limiting T cell overactivation and overproduction of IFN-γ, a key lupus cytokine. p21 did not affect normal T cell responses, revealing differential p21 requirements for autoreactive and normal T cell activity regulation. The underlying concept of these findings suggests potential treatments for lupus and autoimmune lymphoproliferative syndrome, without compromising normal immunity.

Topics: Animals; Apoptosis; Autoimmune Diseases; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Proliferation; Cells, Cultured; Cyclin-Dependent Kinase Inhibitor p21; Immunologic Memory; Interferon-gamma; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Ovalbumin; T-Lymphocytes; Vaccinia virus

Peptide-based therapy is a promising strategy for antigen-specific immunosuppression to treat or even heal autoimmune diseases with significantly reduced adverse effects compared to conventional therapies. However, there has been no major success due to the drawbacks of native peptides, i.e., limited bioavailability. Considering the importance and limitations of peptide-based therapies for treatment of autoimmune diseases, we designed and constructed oligoglycerol (OG)- and polyglycerol (PG)-based peptide conjugates. They were evaluated for their biological activity (in vitro and in vivo), bioavailability, and tolerogenic potential. Among the OG- and PG-peptide constructs, PG-peptide constructs exhibited an extended bioavailability compared to OG-peptide constructs and unconjugated peptide. Interestingly, size, structure, and linker chemistry played a critical role for the tolerogenic capacity of the constructs. The PG-peptide construct bound via an ester linkage was the most tolerogenic conjugate, while the PG-peptide construct bound via an amide induced stronger proliferation, but also higher TNF production and lower frequencies of Foxp3(+) regulatory T-cells. Therefore, we conclude that PG-peptide conjugates bound via an ester linkage are not only promising candidates for tolerogenic vaccination, but also open a new avenue toward the application of peptides for the treatment of autoimmune diseases.

Topics: Adoptive Transfer; Amino Acid Sequence; Animals; Autoimmune Diseases; Biological Availability; Cells, Cultured; Dendritic Cells; Forkhead Transcription Factors; Gene Expression; Glycerol; Immune Tolerance; Immunologic Factors; Mice; Mice, Inbred BALB C; Mice, Transgenic; Molecular Sequence Data; Molecular Targeted Therapy; Ovalbumin; Peptides; Polymers; Receptors, Antigen, T-Cell; Structure-Activity Relationship; T-Lymphocytes, Regulatory; Tumor Necrosis Factor-alpha

Th17 cells are critical for the clearance of extracellular bacteria and fungi, but also contribute to the pathology of autoimmune diseases and allergic inflammation. After exposure to an appropriate cytokine environment, Th17 cells can acquire a Th1-like phenotype, but less is known about their ability to adopt Th2 and Th9 effector programs. To explore this in more detail, we used an IL-17F lineage tracer mouse strain that allows tracking of cells that formerly expressed IL-17F. In vitro-derived Th17 cells adopted signature cytokine and transcription factor expression when cultured under Th1-, Th2-, or Th9-polarizing conditions. In contrast, using two models of allergic airway disease, Th17 cells from the lungs of diseased mice did not adopt Th1, Th2, or Th9 effector programs, but remained stable IL-17 secretors. Although in vitro-derived Th17 cells expressed IL-4Rα, those induced in vivo during allergic airway disease did not, possibly rendering them unresponsive to IL-4-induced signals. However, in vitro-derived, Ag-specific Th17 cells transferred in vivo to OVA and aluminum hydroxide-sensitized mice also maintained IL-17 secretion and did not produce alternative cytokines upon subsequent OVA challenge. Thus, although Th17 cells can adopt new phenotypes in response to some inflammatory environments, our data suggest that in allergic inflammation, Th17 cells are comparatively stable and retain the potential to produce IL-17. This might reflect a cytokine environment that promotes Th17 stability, and allow a broader immune response at tissue barriers that are susceptible to allergic inflammation.

Topics: Aluminum Hydroxide; Animals; Asthma; Autoimmune Diseases; Cell Differentiation; Cell Lineage; Cytokines; Hypersensitivity; Interleukin-17; Lung; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Receptors, Cell Surface; Th1 Cells; Th17 Cells; Th2 Cells

There are several murine models described with features similar to human primary biliary cirrhosis (PBC). Among these models, the one which has the closest serologic features to PBC is a mouse with a T-cell-restricted expression of the dominant negative transforming growth factor β receptor type II (dnTGFβRII). Our work has demonstrated that CD8(+) T cells from dnTGFβRII mice transfer autoimmune cholangitis to Rag1(-/-) recipients. However, it remained unclear whether the autoimmune cholangitis was secondary to an intrinsic function within CD8(+) T cells or due to the abnormal TGFβR environment within which CD8(+) T cells were generated. To address this mechanistic issue, we used our dnTGFβRII, OT-I/Rag1(-/-) , OT-II/Rag1(-/-) mice and in addition generated OT-I/dnTGFβRII/Rag1(-/-) , and OT-II/dnTGFβRII/Rag1(-/-) mice in which the entire T-cell repertoire was replaced with ovalbumin (OVA)-specific CD8(+) or CD4(+) T cells, respectively. Importantly, neither the parental OT-I/dnTGFβRII/Rag1(-/-) mice and/or OT-II/dnTGFβRII/Rag1(-/-) mice developed cholangitis. However, adoptive transfer demonstrated that only transfer of CD8(+) T cells from dnTGFβRII mice but not CD8(+) T cells from OT-I/Rag1(-/-) mice or from OT-I/dnTGFβRII/Rag1(-/-) mice transferred disease. These data were not secondary to an absence of CD4(+) T cell help since a combination of CD8(+) T cells from OT-I/dnTGFβRII/Rag1(-/-) and CD4(+) T cells from OT II/dnTGFβRII/Rag1(-/-) or CD8(+) T cells from OT-I/dnTGFβRII/Rag1(-/-) with CD4(+) T cells from OT-II/Rag1(-/-) mice failed to transfer disease.. Defective TGFβRII signaling, in addition to clonal CD8(+) T cells that target biliary cells, are required for induction of autoimmune cholangitis.

Topics: Adoptive Transfer; Animals; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Cholangitis; Disease Models, Animal; Female; Homeodomain Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; T-Cell Antigen Receptor Specificity

T cells are essential for the development of uveitis and other autoimmune diseases. After initial activation, CD4+ lymphocytes express the co-stimulatory molecule OX40 that plays an important role in T cell proliferation. Cyclin dependent kinase 2 (CdK2) plays a pivotal role in the cell cycle transition from G1 to S phase. In addition, recent research has implicated CdK2 in T cell activation. Thus, we sought to test the immunosuppressive effect of roscovitine, a potent CdK2 inhibitor, on CD4+ T cell activation, proliferation, and function.. Mouse CD4+ T cells were activated by anti-CD3 and anti-CD28 antibodies. The expression of OX40, CD44, and CdK2 were analyzed by flow cytometry. In addition, cell cycle progression and apoptosis of control and roscovitine-treated T lymphocytes were measured by BrdU incorporation and annexin V assay, respectively. Furthermore, the immunoregulatory effect of roscovitine was evaluated in both ovalbumin-induced uveitis and experimental autoimmune uveitis (EAU) models.. In this study, we found that T cell activation induced OX40 expression. Cell cycle analysis showed that more CD4+OX40+ cells entered S phase than OX40- T cells. Concurrently, CD4+OX40+ cells had a higher level of CdK2 expression. Roscovitine treatment blocked activated CD4+ cells from entering S phase. In addition, roscovitine not only reduced the viability of CD4+ lymphocytes but also suppressed T cell activation and cytokine production. Finally, roscovitine significantly attenuated the severity of T cell-dependent, OX40-enhanced uveitis.. These results implicate CdK2 in OX40-augmented T cell response and expansion. Furthermore, this study suggests that roscovitine is a novel, promising, therapeutic agent for treating T cell-mediated diseases such as uveitis.

Topics: Animals; Antibodies; Autoimmune Diseases; CD28 Antigens; CD3 Complex; CD4-Positive T-Lymphocytes; Cell Proliferation; Cyclin-Dependent Kinase 2; G1 Phase; Gene Expression; Hyaluronan Receptors; Immunologic Factors; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; Protein Kinase Inhibitors; Purines; Receptors, OX40; Roscovitine; S Phase; Uveitis

The B subunit of E. coli heat-labile enterotoxin (EtxB) protects against the development of T helper type 1 (Th1)-mediated autoimmune pathologies in mice. Protection was transferable with splenic CD4(+) T cells and was less effective following CD25 depletion; implying a T regulatory cell (Treg)-mediated process. We hypothesized that if this were the case, then EtxB would also control a Th2-mediated disorder. We tested the effect of EtxB treatment on asthma development in ovalbumin (OVA)-sensitized mice. EtxB treatment diminished eosinophilia in bronchoalveolar lavage samples, reduced OVA-specific immunoglobulin E and interleukin 4 production locally and systemically, and reduced airway hyper-reactivity. EtxB induced a dose-dependent increase in Foxp3(+)CD4(+) T cells, and adoptive transfer of splenic CD4(+) T cells partially suppressed lung pathology. Importantly, EtxB treatment increased OVA-specific CD4(+)Foxp3(+) T cells in the lung and systemically. These data demonstrate that EtxB modulates the differentiation of allergen-specific T cells causing inducible Treg induction and preventing disease.

Topics: Animals; Asthma; Autoimmune Diseases; Bacterial Toxins; CD4 Antigens; Cells, Cultured; Enterotoxins; Eosinophils; Escherichia coli Proteins; Female; Immunity, Humoral; Immunoglobulin E; Immunosuppression Therapy; Interleukin-4; Lymphocyte Activation; Lymphocyte Depletion; Mice; Mice, Inbred BALB C; Ovalbumin; T-Lymphocytes, Regulatory; Th2 Cells

To investigate the effect of systemic or local TNF-α inhibition with etanercept on experimental autoimmune uveoretinitis (EAU).. EAU was induced by immunizing B10.RIII mice with IRBPp161-180 or by adoptively transferring uveitogenic splenocytes. Mice received systemic or local treatment with etanercept in the afferent or efferent phase. For systemic treatment, mice were injected intraperitoneally. For local treatment, etanercept was injected intravitreally or subconjunctivally. Control mice received PBS. EAU scores were determined histologically. Splenic cells were assessed for [(3)H]thymidine incorporation. ELISA was performed to measure levels of cytokines produced by splenocytes. Vitreous cavity-associated immune deviation (VCAID) was induced by intravitreally injecting ovalbumin and evaluated by measuring DTH reaction.. After systemic treatment with etanercept in the afferent phase, EAU disease scores, IRBP-specific cell proliferation, and production of Th1, Th2, and Th17 cytokines were reduced. EAU also improved after intravitreal etanercept treatment in the afferent phase, with unaltered IRBP-specific proliferation, reduced IFN-γ, but increased IL-6 and IL-10 secretion. VCAID induction was impaired after intravitreal etanercept treatment. No amelioration of EAU or reduction in IRBP-specific cell response was found after systemic or intravitreal treatment in the efferent phase or after subconjunctival treatment. After adoptive transfer, etanercept- and PBS-treated recipients showed similar disease severity and antigen-specific proliferation of splenocytes.. It can be concluded that TNF-α participates mainly in the immunopathology in the induction phase of EAU. The mechanism of action underlying EAU improvement may be different for local and systemic etanercept treatment.

Topics: Adoptive Transfer; Animals; Autoimmune Diseases; Cell Proliferation; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Etanercept; Eye Proteins; Immunoglobulin G; Immunosuppressive Agents; Injections, Intraperitoneal; Intravitreal Injections; Mice; Ovalbumin; Receptors, Tumor Necrosis Factor; Retinitis; Retinol-Binding Proteins; T-Lymphocytes, Helper-Inducer; Tumor Necrosis Factor-alpha; Uveitis, Posterior; Vitreous Body

Transgenic (Tg) mouse models of autoimmunity have been used to express model antigens that can be recognized by T cells or by autoantibodies. To identify mechanisms of CD8-mediated tissue-specific autoimmune reactions and to identify potential treatments, we generated a double-transgenic (DTg) murine model of autoimmunity by crossing keratin-14 (K14)-soluble chicken ovalbumin (sOVA) mice, which express sOVA predominantly in external ear skin, with OT-I mice whose CD8 T cells express Vα2/Vβ5 regions of the TCR and are specific for SIINFEKL peptide (chicken ovalbumin (OVA) peptide 257-264) in association with class I major histocompatibility complex. The K14-sOVA/OT-I DTg mice develop a destructive process selectively targeting the external ear pinnae in the first 6 days of life. The ear bud area develops an intense inflammatory infiltrate of OT-I cells. Administration of the SIINFEKL peptide intravenously to pregnant F1 (filial 1, first filial generation of animal offspring from cross-mating two parental types) mice and subsequently intraperitoneally to newborn pups resulted in normal external ear development. Treatment with this self-peptide markedly reduced OT-I cell numbers, as well as downregulated the CD8 co-receptor. This model can be useful in studying localized, tissue-specific, immune-mediated skin disease, and provide information about potential therapies for autoimmune diseases in which specific molecular targets are known.

Topics: Animals; Autoimmune Diseases; Autoimmunity; CD8-Positive T-Lymphocytes; Disease Models, Animal; Down-Regulation; Female; Keratin-14; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Peptide Fragments; Pregnancy; Receptors, Antigen, T-Cell; Receptors, Antigen, T-Cell, alpha-beta; Skin Diseases

In this issue, Paek et al. describe two phenomena. First, they show that intermediate concentrations of a "transgenic" autoantigen may cause a lichen planus-like autoimmune disease. Second, and more importantly, they show that high doses of peptide antigen suppress the expression of the T-cell receptor and coreceptors, particularly CD8, and that this suppression improves this T-cell-mediated, destructive inflammatory skin disease that is similar to erosive lichen planus.

Topics: Animals; Autoimmune Diseases; Autoimmunity; CD8-Positive T-Lymphocytes; Female; Male; Ovalbumin; Peptide Fragments; Pregnancy; Skin Diseases

T cells secrete bioactive exosomes (EXO), but the potential immunoregulatory effect of T-cell EXO is largely unknown. In this study, we generated activated ovalbumin (OVA)-specific CD4(+) T cells in vitro via coculture of OVA-pulsed dendritic cells (DC(OVA)) with naive CD4(+) T cells derived from OVA-specific T-cell receptor (TCR) transgenic OTII mice. CD4(+) T-cell EXO were then purified from the CD4(+) T-cell culture supernatants by differential ultracentrifugation. CD4(+) T-cell EXO exhibited the 'saucer' shape that is characteristic of EXO with a diameter between 50 and 100 nm, as assessed by electron microscopy, and contained the EXO-associated proteins LAMP-1, TCR and lymphocyte function associated antigen-1 (LFA-1), as determined by western blot. Flow cytometric analysis showed that CD4(+) T-cell EXO expressed CD4(+) T-cell markers (CD4, TCR, LFA-1, CD25 and Fas ligand), but to a lesser extent than CD4(+) T cells. We demonstrated that DC(OVA) took up CD4(+) T-cell EXO via peptide/major histocompatibility complex (pMHC) II/TCR and CD54/LFA-1 interactions. OVA-specific CD4(+) T-cell EXO from OTII mice, but not ConA-stimulated polyclonal CD4(+) T-cell EXO from wild-type C57BL/6 mice inhibited DC(OVA)-stimulated in vitro CD4(+) T-cell proliferation and in vivo CD8(+) cytotoxic T lymphocyte (CTL) responses and antitumor immunity against OVA-expressing B16 melanoma BL6-10(OVA) cells. In addition, EXO derived from a T-cell hybridoma cell line, MF72.2D9, expressing an OVA-specific CD4(+) TCR, had a similar inhibitory effect as OTII CD4(+) T-cell EXO on CTL-mediated antitumor immunity. Taken together, our data indicate that antigen-specific T-cell EXO may serve as a new type of immunosuppressive reagent for use in transplant rejection and treatment of autoimmune diseases.

Topics: Animals; Autoimmune Diseases; Biomarkers; CD4-Positive T-Lymphocytes; Cell Line, Tumor; Cytotoxicity, Immunologic; Dendritic Cells; Exosomes; Female; Graft Rejection; Immunity; Immunomodulation; Lymphocyte Activation; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neoplasm Transplantation; Ovalbumin; T-Lymphocytes, Cytotoxic

Although NKT cells have been implicated in diverse immunomodulatory responses, the effector mechanisms underlying the NKT cell-mediated regulation of pathogenic T helper cells are not well understood. Here, we show that invariant NKT cells inhibited the differentiation of CD4(+) T cells into Th17 cells both in vitro and in vivo. The number of IL-17-producing CD4(+) T cells was reduced following co-culture with purified NK1.1(+) TCR(+) cells from WT, but not from CD1d(-/-) or Jα18(-/-) , mice. Co-cultured NKT cells from either cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) or WT mice efficiently inhibited Th17 differentiation. The contact-dependent mechanisms of NKT cell-mediated regulation of Th17 differentiation were confirmed using transwell co-culture experiments. On the contrary, the suppression of Th1 differentiation was dependent on IL-4 derived from the NKT cells. The in vivo regulatory capacity of NKT cells on Th17 cells was confirmed using an experimental autoimmune uveitis model induced with human IRBP(1-20) (IRBP, interphotoreceptor retinoid-binding protein) peptide. NKT cell-deficient mice (CD1d(-/-) or Jα18(-/-) ) demonstrated an increased disease severity, which was reversed by the transfer of WT or cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) NKT cells. Our results indicate that invariant NKT cells inhibited autoimmune uveitis predominantly through the cytokine-independent inhibition of Th17 differentiation.

Topics: Adoptive Transfer; Animals; Antigens, CD1d; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Cell Communication; Cell Count; Cell Differentiation; Cytokines; Disease Models, Animal; Eye; Eye Proteins; Interleukin-4; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Natural Killer T-Cells; Ovalbumin; Peptide Fragments; Retinol-Binding Proteins; Th1 Cells; Th17 Cells; Uveitis; Vaccination

The role of CD4(+) T cells in bladder autoimmune inflammation has not been identified because of the lack of a proper animal model. We investigated CD4(+) T-cell responses to bladder urothelial ovalbumin (OVA), a model self-antigen (Ag), in transgenic URO-OVA mice. The expression of bladder urothelial OVA rendered mice unresponsive to OVA and resulted in quick clearance of Ag-specific CD4(+) T cells. Adoptive transfer of naive OVA-specific CD4(+) T cells led to exogenous T-cell proliferation, activation, and bladder infiltration but no inflammatory induction. In contrast, adoptive transfer of preactivated OVA-specific CD4(+) T cells induced bladder inflammation. Studies further demonstrated that CD4(+) T cells induced bladder inflammation in URO-OVA mice depleted of CD8(+) T cells or deficient in the recombinase activating gene-1 (Rag-1(-/-)). These results indicate that urothelial Ag-specific CD4(+) T cells can function as direct effector cells to induce bladder autoimmune inflammation independent of CD8(+) T cells.

Topics: Adoptive Transfer; Animals; Autoimmune Diseases; Autoimmunity; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cystitis; Immune Tolerance; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Urothelium

Biglycan is a proteoglycan ubiquitously present in extracellular matrix of a variety of organs, including heart, and it was reported to be overexpressed in myocardial infarction. Myocardial infarction may be complicated by perimyocarditis through unknown mechanisms. Our aim was to investigate the capacity of TLR2/TLR4 ligand biglycan to enhance the presentation of specific Ags released upon cardiomyocyte necrosis. In vitro, OVA-pulsed bone marrow-derived dendritic cells from wild-type (WT; C57BL/6) and TLR2-, TLR4-, MyD88-, or TRIF-deficient mice were cotreated with LPS, biglycan, or vehicle and incubated with OVA-recognizing MHC I- or MHC II-restricted T cells. Biglycan enhanced OVA-specific cross-priming by >80% to MHC I-restricted T cells in both TLR2- and TLR4-pathway-dependent manners. Accordingly, biglycan-induced cross-priming by both MyD88- and TRIF-deficient dendritic cells (DCs) was strongly diminished. OVA-specific activation of MHC II-restricted T cells was predominantly TLR4 dependent. Our first in vivo correlate was a model of experimental autoimmune perimyocarditis triggered by injection of cardiac Ag-pulsed DCs (BALB/c). Biglycan-treated DCs triggered perimyocarditis to a comparable extent and intensity as LPS-treated DCs (mean scores 1.3 ± 0.3 and 1.5 ± 0.4, respectively). Substitution with TLR4-deficient DCs abolished this effect. In a second in vivo approach, WT and biglycan-deficient mice were followed 2 wk after induction of myocardial infarction. WT mice demonstrated significantly greater myocardial T lymphocyte infiltration in comparison with biglycan-deficient animals. We concluded that the TLR2/4 ligand biglycan, a component of the myocardial matrix, may enhance Ag-specific T cell priming, potentially via MyD88 and TRIF, and stimulate autoimmune perimyocarditis.

Topics: Adaptor Proteins, Vesicular Transport; Amino Acid Sequence; Animals; Antigen Presentation; Autoimmune Diseases; Biglycan; Cells, Cultured; Coculture Techniques; Cross-Priming; Epitopes, T-Lymphocyte; HEK293 Cells; Humans; Ligands; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Molecular Sequence Data; Myeloid Differentiation Factor 88; Myocarditis; NIH 3T3 Cells; Ovalbumin; Pericarditis; Signal Transduction; T-Lymphocyte Subsets; Toll-Like Receptor 2; Toll-Like Receptor 4; Up-Regulation

Immune homeostasis in tissues is achieved through a delicate balance between pathogenic T-cell responses directed at tissue-specific antigens and the ability of the tissue to inhibit these responses. The mechanisms by which tissues and the immune system communicate to establish and maintain immune homeostasis are currently unknown. Clinical evidence suggests that chronic or repeated exposure to self antigen within tissues leads to an attenuation of pathological autoimmune responses, possibly as a means to mitigate inflammatory damage and preserve function. Many human organ-specific autoimmune diseases are characterized by the initial presentation of the disease being the most severe, with subsequent flares being of lesser severity and duration. In fact, these diseases often spontaneously resolve, despite persistent tissue autoantigen expression. In the practice of antigen-specific immunotherapy, allergens or self antigens are repeatedly injected in the skin, with a diminution of the inflammatory response occurring after each successive exposure. Although these findings indicate that tissues acquire the ability to attenuate autoimmune reactions upon repeated responses to antigens, the mechanism by which this occurs is unknown. Here we show that upon expression of self antigen in a peripheral tissue, thymus-derived regulatory T cells (T(reg) cells) become activated, proliferate and differentiate into more potent suppressors, which mediate resolution of organ-specific autoimmunity in mice. After resolution of the inflammatory response, activated T(reg) cells are maintained in the target tissue and are primed to attenuate subsequent autoimmune reactions when antigen is re-expressed. Thus, T(reg) cells function to confer 'regulatory memory' to the target tissue. These findings provide a framework for understanding how T(reg) cells respond when exposed to self antigen in peripheral tissues and offer mechanistic insight into how tissues regulate autoimmunity.

Topics: Animals; Autoantigens; Autoimmune Diseases; Autoimmunity; Cell Differentiation; Cell Proliferation; Gene Expression Regulation; Immunologic Memory; Mice; Mice, Transgenic; Models, Animal; Ovalbumin; Skin Diseases; T-Lymphocytes, Regulatory; Time Factors

The entry of autoreactive T cells into the pancreas is a critical checkpoint in the development of autoimmune diabetes. In this study, we identify a role for B1 cells in this process using the DO11 x RIP-mOVA mouse model. In transgenic mice with islet-specific T cells, but no B cells, T cells are primed in the pancreatic lymph node but fail to enter the pancreas. Reconstitution of the B1 cell population by adoptive transfer permits extensive T cell pancreas infiltration. Reconstituted B1 cells traffic to the pancreas and modify expression of adhesion molecules on pancreatic vasculature, notably VCAM-1. Despite substantial pancreas infiltration, islet destruction is minimal unless regulatory T cells are depleted. These data identify a role for B1 cells in permitting circulating islet-specific T cells to access their Ag-bearing tissue and emphasize the existence of multiple checkpoints to regulate autoimmune disease.

Topics: Adoptive Transfer; Animals; Autoimmune Diseases; B-Lymphocyte Subsets; CD8-Positive T-Lymphocytes; Cell Movement; Cells, Cultured; Diabetes Mellitus, Experimental; Islets of Langerhans; Lymphocyte Depletion; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, Transgenic; Ovalbumin; Rats; Vascular Cell Adhesion Molecule-1

Achieving remission in rheumatoid arthritis (RA) remains elusive despite current biological therapeutics. Consequently, interest has increased in strategies to re-establish immune tolerance to provide long-term disease suppression. Although dendritic cells (DC) are prime candidates in initiating autoreactive T cell responses, and their presence within the synovial environment suggests a role in generation and maintenance of autoreactive, synovial T cell responses, their functional importance remains unclear. We investigated the contribution made by plasmacytoid DCs (pDCs) in the spontaneous breach of tolerance to arthritis-related self proteins, including rheumatoid factor, citrullinated peptide, and type II collagen observed in a novel arthritis model. Selective pDC depletion in vivo enhanced the severity of articular pathology and enhanced T and B cell autoimmune responses against type II collagen. pDC may offer a net anti-inflammatory function in the context of articular breach of tolerance. Such data will be vital in informing DC modulatory/therapeutic approaches.

Topics: Adoptive Transfer; Animals; Arthritis, Experimental; Autoantibodies; Autoantigens; Autoimmune Diseases; Cells, Cultured; Collagen Type II; Dendritic Cells; Female; Freund's Adjuvant; Mice; Mice, Inbred BALB C; Mice, Transgenic; Ovalbumin; Peptides, Cyclic; Rheumatoid Factor; Self Tolerance; Th1 Cells

The B7 family member programmed death-1 ligand (PD-L1) has been shown to play an inhibitory role in the regulation of T cell responses in several organs. However, the role of PD-L1 in regulating tolerance to self-Ags of the small intestine has not been previously addressed. In this study, we investigated the role of PD-L1 in CD8(+) T cell tolerance to an intestinal epithelium-specific Ag using the iFABP-tOVA transgenic mouse model, in which OVA is expressed as a self-Ag throughout the small intestine. Using adoptive transfer of naive OVA-specific CD8(+) T cells, we show that loss of PD-1:PD-L1 signaling, by either Ab-mediated PD-L1 blockade or transfer of PD-1(-/-) T cells, leads to considerable expansion of OVA-specific CD8(+) T cells and their differentiation into effector cells capable of producing proinflammatory cytokines. A fatal CD8(+) T cell-mediated inflammatory response develops rapidly against the small bowel causing destruction of the epithelial barrier, severe blunting of intestinal villi, and recruitment and activation of myeloid cells. This response is highly specific because immune destruction selectively targets the small intestine but not other organs. Collectively, these results indicate that loss of the PD-1:PD-L1 inhibitory pathway breaks CD8(+) T cell tolerance to intestinal self-Ag, thus leading to severe enteric autoimmunity.

Topics: Adoptive Transfer; Animals; Antigens, Surface; Apoptosis Regulatory Proteins; Autoantigens; Autoimmune Diseases; B7-1 Antigen; B7-H1 Antigen; CD8-Positive T-Lymphocytes; Cell Differentiation; Enteritis; Flow Cytometry; Immune Tolerance; Immunity, Mucosal; Intestines; Lymphocyte Activation; Membrane Glycoproteins; Mice; Mice, Transgenic; Ovalbumin; Peptides; Programmed Cell Death 1 Receptor

The progression of kidney disease to renal failure correlates with infiltration of mononuclear immune cells into the tubulointerstitium. These infiltrates contain macrophages, DCs, and T cells, but the role of each cell type in disease progression is unclear. To investigate the underlying immune mechanisms, we generated transgenic mice that selectively expressed the model antigens ovalbumin and hen egg lysozyme in glomerular podocytes (NOH mice). Coinjection of ovalbumin-specific transgenic CD8+ CTLs and CD4+ Th cells into NOH mice resulted in periglomerular mononuclear infiltrates and inflammation of parietal epithelial cells, similar to lesions frequently observed in human chronic glomerulonephritis. Repetitive T cell injections aggravated infiltration and caused progression to structural and functional kidney damage after 4 weeks. Mechanistic analysis revealed that DCs in renal lymph nodes constitutively cross-presented ovalbumin and activated CTLs. These CTLs released further ovalbumin for CTL activation in the lymph nodes and for simultaneous presentation to Th cells by distinct DC subsets residing in the kidney tubulointerstitium. Crosstalk between tubulointerstitial DCs and Th cells resulted in intrarenal cytokine and chemokine production and in recruitment of more CTLs, monocyte-derived DCs, and macrophages. The importance of DCs was established by the fact that DC depletion rapidly resolved established kidney immunopathology. These findings demonstrate that glomerular antigen-specific CTLs and Th cells can jointly induce renal immunopathology and identify kidney DCs as a mechanistic link between glomerular injury and the progression of kidney disease.

Topics: Animals; Antigen Presentation; Autoimmune Diseases; Cell Movement; Dendritic Cells; Disease Models, Animal; Glomerulonephritis; Kidney; Leukocytes, Mononuclear; Lymph Nodes; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Muramidase; Ovalbumin; Podocytes; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Helper-Inducer

Little is known about the potential role of T cells in the inflammatory renal disease glomerulonephritis (GN). GN has been historically viewed as a product of immune complex-mediated complement activation, and the presence of autoantibodies made identifying T cell-specific effector contributions difficult to elucidate. In this issue of the JCI, Heymann et al. generate what they believe to be a novel, transgenic murine model of GN, demonstrating a direct role for CD8+ T cells, activated CD4+ T cells, and DCs in the pathogenesis of GN (see the related article beginning on page 1286).

Topics: Animals; Antigen Presentation; Autoimmune Diseases; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Dendritic Cells; Disease Models, Animal; Glomerulonephritis; Kidney; Lymph Nodes; Lymphocyte Activation; Mice; Mice, Transgenic; Ovalbumin; Podocytes; T-Lymphocytes

Although the pathogenic role of B cells and CD4 T cells has been studied extensively, less is known about the role of CD8 T cells in autoimmunity and self-tolerance. To evaluate the role of CD8 T cells in autoimmunity and its modulation using self-peptides, we used mice expressing soluble OVA (sOVA) under control of the keratin-14 promoter. Spontaneous autoimmunity occurred when sOVA mice were crossed with OT-I mice, whose CD8 T cells carry a Valpha2/Vbeta5-transgenic TCR with specificity for the OVA(257-264) peptide. Eighty-three percent of OVA/OT-I mice died during the first 2 wk of life due to multiple organ inflammation. In contrast, preventive or therapeutic OVA(257-264) peptide injections induced a dose-dependent increase in survival. Healthy survivors exhibited reductions in peripheral CD8 T cells, CD8 coreceptor, and Valpha2 expression. Furthermore, CD8 T cells from healthy mice were anergic and could not be activated by exogenous IL-2. A block in IL-2/IL-7 signaling via the STAT5 pathway provided the basis for low surface expression of the CD8 coreceptor and failure of IL-2 to break CD8 T cell anergy. Thus, the soluble TCR ligand triggered multiple tolerance mechanisms in these sOVA/OT-I mice, making this treatment approach a potential paradigm for modulating human autoimmune diseases.

Topics: Animals; Autoimmune Diseases; CD8 Antigens; Chickens; Clonal Anergy; Down-Regulation; Immune Tolerance; Interleukin-2; Interleukin-7; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; Peptide Fragments; Receptors, Antigen, T-Cell; Receptors, Antigen, T-Cell, alpha-beta; Signal Transduction; Solubility; STAT5 Transcription Factor; Survival Analysis

Immature dendritic cells (DCs) sample tissue-specific antigens (TSAs) and process them for "crosspresentation" via major histocompatibility complex (MHC) class I and II molecules. Findings with adoptively transferred T cell receptor (TCR)-transgenic CD8+ T cells in transgenic mice expressing model TSA indicate that this process contributes to tolerance induction of CD8+ T cells, a phenomenon termed "crosstolerance." However, up to now it has been unknown whether "crosstolerance" can also control autoimmune T cells specific for physiological nontransgenic TSA. Here, we showed that a DC-specific deficiency in uptake of apoptotic material inhibits crosspresentation in vivo. This defect allowed the accumulation of fully functional autoreactive CD8+ T cells that could be activated for autoimmune attack in peripheral lymphoid organs. Thus, our data demonstrate the importance of crosstolerance induction by DCs as a vital instrument for controlling self-reactive T cells from the peripheral repertoire and preventing autoimmune disease.

Topics: Animals; Antigens; Apoptosis; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Cell Line; Cross-Priming; Dendritic Cells; Immune Tolerance; Listeria monocytogenes; Lymphoid Tissue; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; rac1 GTP-Binding Protein

To investigate the efficacy of the B subunit of Escherichia coli heat-labile enterotoxin (EtxB) in the treatment of ocular autoimmune disease. Murine experimental autoimmune uveoretinitis (EAU) is an animal model of autoimmune posterior uveitis initiated by retinal antigen-specific Th1 and Th17 CD4(+) T cells, which activate myeloid cells, inducing retinal damage. EtxB is a potent immune modulator that ameliorates other Th1-mediated autoimmune diseases, enhancing regulatory T-cell activity.. EAU was induced in B10.RIII mice by immunization with peptide hIRBP(161-180). Disease severity was measured by clinical and histologic assessment, and functional responses of macrophages (Mphis) and T cells were assessed, both in vivo and in cocultures in vitro. EtxB was administered intranasally daily for 4 days, starting either 3 days before or 3 days after EAU induction.. Preimmunization treatment with EtxB protected mice from EAU, limiting both the number and the activation status of retinal infiltrating immune cells. Treatment after EAU induction did not alter the disease course, despite suppression of IFN-gamma. Although EtxB treatment of in vitro cocultures of T cells and Mphis increased IL-10 production, EtxB treatment in vivo increased the proportion and number of IL-17-producing CD4(+) cells infiltrating the eye.. EtxB preimmunization protects mice from EAU induction by inhibiting Th1 responses, but the resultant reduction in IFN-gamma responses by EtxB does not effect infiltration or structural damage in established EAU, where Th17 responses predominate. These data highlight the critical importance of the dynamics of T-cell phenotype and infiltration during EAU when considering immunomodulatory therapy.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; Bacterial Toxins; Bone Marrow Cells; Cell Division; Disease Models, Animal; Enterotoxins; Escherichia coli Proteins; Macrophages; Mice; Mice, Inbred C57BL; Ovalbumin; Peptide Fragments; Retinitis; Retinol-Binding Proteins; T-Lymphocytes; T-Lymphocytes, Helper-Inducer; Th1 Cells; Uveitis

The effort to explore the specific autoimmune mechanisms of urinary bladder has long been hindered due to a lack of proper animal models. To better elucidate this issue, we developed a novel line of transgenic (Tg) mice, designated as URO-OVA mice, that express the model Ag OVA as a "self"-Ag on the bladder epithelium. URO-OVA mice are naturally tolerant to OVA and show no response to OVA stimulation. Adoptive transfer of naive OVA-specific T cells showed cell proliferation, activation, and infiltration but no bladder histopathology. In contrast, adoptive transfer of activated OVA-specific T cells induced OVA-mediated histological bladder inflammation. Increased mast cells and up-regulated mRNA expressions of TNF-alpha, nerve growth factor, and substance P precursor were also observed in the inflamed bladder. To further facilitate bladder autoimmunity study, we crossbred URO-OVA mice with OVA-specific CD8(+) TCR Tg mice (OT-I mice) to generate a dual Tg line URO-OVA/OT-I mice. The latter mice naturally acquire clonal deletion for autoreactive OT-I CD8(+) T cells (partial deletion in the thymus and severe deletion in the periphery). Despite this clonal deletion, URO-OVA/OT-I mice spontaneously develop autoimmune cystitis at 10 wk of age. Further studies demonstrated that the inflamed bladder contained infiltrating OT-I CD8(+) T cells that had escaped clonal deletion and gained effector functions before developing histological bladder inflammation. Taken together, we demonstrate for the first time that the bladder epithelium actively presents self-Ag to the immune system and induces CD8(+) T cell tolerance, activation, and autoimmune response.

Topics: Adenoviridae; Animals; Antigen Presentation; Autoantigens; Autoimmune Diseases; Autoimmunity; CD8-Positive T-Lymphocytes; Cystitis; Epithelium; Immune Tolerance; Lymphocyte Activation; Mice; Mice, Transgenic; Ovalbumin; Transfection; Urinary Bladder

The anaphylatoxins C3a and C5a are involved in the pathophysiology of microbial as well as allergic inflammation in the lungs. Besides their expression in leukocytes, receptors for C3a and C5a (C3aR and C5aR) have been noted in alveolar and bronchial epithelial cells, bronchial smooth muscle cells as well as in vascular endothelial and smooth muscle cells of normal and inflamed human and murine lungs. Recently, however, expression of anaphylatoxin receptors in parenchymal cells of the lung (and kidney) has been challenged. Using well-characterized monoclonal antibodies (mabs) against murine and rat anaphylatoxin receptors, we reexamined the pulmonary distribution of C3aR and C5aR. Immunohistochemistry was performed on frozen sections of lung tissues from normal mice and rats as well as from animals subjected to lipopolysaccharide (LPS)-induced inflammation or from MRL/lpr mice suffering from autoimmune disease. Furthermore, ovalbumin (OVA)-induced models of allergic asthma in the rat and mouse were investigated. Prominent expression of both anaphylatoxin receptors was detectable in resident as well as infiltrating leukocytes. No C3aR protein was observed in alveolar macrophages. Upon LPS- and OVA-challenge as well as in autoimmune inflammation, numbers of infiltrating leukocytes expressing prominent amounts of anaphylatoxin receptors increased. Even under these highly inflammatory conditions, however, expression of C3aR and C5aR was not inducible in parenchymal cells. Thus, our findings identify infiltrating leukocytes as a prominent source of anaphylatoxin receptors in inflamed lungs. A direct involvement of parenchymal cells in anaphylatoxin-mediated pulmonary inflammation is unlikely.

Topics: Animals; Antibodies, Monoclonal; Asthma; Autoimmune Diseases; Disease Models, Animal; Endothelial Cells; Leukocytes; Lipopolysaccharides; Lung; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Inbred MRL lpr; Muscle, Smooth, Vascular; Ovalbumin; Pneumonia; Rats; Rats, Inbred BN; Rats, Inbred Lew; Receptor, Anaphylatoxin C5a; Receptors, Complement

To explore the interactions between regulatory T cells and pathogenic effector cytokines, we have developed a model of a T cell-mediated systemic autoimmune disorder resembling graft-versus-host disease. The cytokine responsible for tissue inflammation in this disorder is interleukin (IL)-17, whereas interferon (IFN)-gamma produced by Th1 cells has a protective effect in this setting. Because of the interest in potential therapeutic approaches utilizing transfer of regulatory T cells and inhibition of the IL-2 pathway, we have explored the roles of these in the systemic disease. We demonstrate that the production of IL-17 and tissue infiltration by IL-17-producing cells occur and are even enhanced in the absence of IL-2. Regulatory T cells favor IL-17 production but prevent the disease when administered early in the course by suppressing expansion of T cells. Thus, the pathogenic or protective effects of cytokines and the therapeutic capacity of regulatory T cells are crucially dependent on the timing and the nature of the disease.

Topics: Adoptive Transfer; Alopecia; Animals; Autoimmune Diseases; Body Weight; CD4-Positive T-Lymphocytes; Disease Models, Animal; DNA-Binding Proteins; Female; Graft vs Host Disease; Inflammation; Interferon-gamma; Interleukin-17; Interleukin-2; Interleukin-4; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, Transgenic; Ovalbumin; Skin; T-Box Domain Proteins; T-Lymphocytes; T-Lymphocytes, Regulatory

In the present study, we investigated the involvement of macrophage-inflammatory protein-1alpha (MIP-1alpha)[CC chemokine ligand 3 (CCL3)], MIP-1beta[CCL4], regulated on activation, normal T expressed and secreted (RANTES)[CCL5], and CC chemokine receptors (CCRs) on neutrophil migration in murine immune inflammation. Previously, we showed that ovalbumin (OVA)-triggered neutrophil migration in immunized mice depends on the sequential release of tumor necrosis factor alpha (TNF-alpha) and leukotriene B(4)(LTB(4)). Herein, we show increased mRNA expression for MIP-1alpha[CCL3], MIP-1beta[CCL4], RANTES[CCL5], and CCR1 in peritoneal cells harvested from OVA-challenged, immunized mice, as well as MIP-1alpha[CCL3] and RANTES[CCL5] but not MIP-1beta[CCL4] proteins in the peritoneal exudates. OVA-induced neutrophil migration response was muted in immunized MIP-1alpha[CCL3](-/-) mice, but it was not inhibited by treatment with antibodies against RANTES[CCL5] or MIP-1beta[CCL4]. MIP-1alpha[CCL3] mediated neutrophil migration in immunized mice through induction of TNF-alpha and LTB(4) synthesis, as these mediators were detected in the exudates harvested from OVA-challenged immunized wild-type but not MIP-1alpha[CCL3](-/-) mice; administration of MIP-1alpha[CCL3] induced a dose-dependent neutrophil migration, which was inhibited by treatment with an anti-TNF-alpha antibody in TNF receptor 1 (p55(-/-))-deficient mice or by MK 886 (a 5-lipoxygenase inhibitor); and MIP-1alpha[CCL3] failed to induce LTB(4) production in p55(-/-) mice. MIP-1alpha[CCL3] used CCR1 to promote neutrophil recruitment, as OVA or MIP-1alpha[CCL3] failed to induce neutrophil migration in CCR1(-/-) mice, in contrast to CCR5(-/-) mice. In summary, we have demonstrated that neutrophil migration observed in this model of immune inflammation is mediated by MIP-1alpha[CCL3], which via CCR1, induces the sequential release of TNF-alpha and LTB(4). Therefore, whether a similar pathway mediates neutrophil migration in human immune-inflammatory diseases, the development of specific CCR1 antagonists might have a therapeutic potential.

Topics: Animals; Antibodies; Autoimmune Diseases; Chemokine CCL3; Chemokine CCL4; Chemokine CCL5; Chemokines, CC; Chemotaxis, Leukocyte; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Inflammation; Leukotriene B4; Macrophage Inflammatory Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Ovalbumin; Receptors, CCR1; Receptors, Chemokine; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; RNA, Messenger; Signal Transduction; Tumor Necrosis Factor Decoy Receptors; Tumor Necrosis Factor-alpha; Up-Regulation

The immune privilege that exists in the eye is maintained by various mechanisms. One of the best studied is a form of systemic tolerance termed anterior chamber-associated immune deviation (ACAID). We have investigated the mechanisms by which ocular inflammation associated with the vitreous cavity (VC) is reduced, by injecting either ovalbumin (OVA) or allogeneic splenocytes into the VCs of mice, and assessed the effect of this on delayed type hypersensitivity (DTH) responses. After antigen inoculation into the VC, antigen-specific DTH responses were significantly impaired and we named this phenomenon 'vitreous cavity-associated immune deviation' (VCAID). VCAID could also be induced by inoculating antigen-pulsed macrophages into the VC. However, VCAID did not develop either in mice with inflamed eyes, whether as a result of experimental autoimmune uveitis or coadministration of interleukin (IL)-6 in the VC, or in knockout mice deficient for natural killer T (NKT) cells. Finally, we found that so-called 'hyalocytes' are the only cells present in the VCs of normal mice, uniformly distributed on the retinal surface. Interestingly, they express F4/80, suggesting that hyalocytes are candidate antigen-presenting cells (APCs) responsible for mediating VCAID. As for the anterior chamber model, systemic tolerance can be induced in the VC in non-inflamed eyes and in the presence of invariant NKT cells.

Topics: Animals; Antigen-Presenting Cells; Antigens; Antigens, CD1; Antigens, CD1d; Autoimmune Diseases; Female; Hypersensitivity, Delayed; Immune Tolerance; Interleukin-6; Killer Cells, Natural; Macrophages; Mice; Mice, Inbred C57BL; Microscopy, Electron; Ovalbumin; Retina; Spleen; Uveitis; Vitreous Body

The current view holds that chronic autoimmune diseases are driven by the continuous activation of autoreactive B and T lymphocytes. However, despite the use of potent immunosuppressive drugs designed to interfere with this activation the production of autoantibodies often persists and contributes to progression of the immunopathology. In the present study, we analyzed the life span of (auto)antibody-secreting cells in the spleens of NZB x NZW F1 (NZB/W) mice, a murine model of systemic lupus erythematosus. The number of splenic ASCs increased in mice aged 1-5 mo and became stable thereafter. Less than 60% of the splenic (auto)antibody-secreting cells were short-lived plasmablasts, whereas 40% were nondividing, long-lived plasma cells with a half-life of >6 mo. In NZB/W mice and D42 Ig heavy chain knock-in mice, a fraction of DNA-specific plasma cells were also long-lived. Although antiproliferative immunosuppressive therapy depleted short-lived plasmablasts, long-lived plasma cells survived and continued to produce (auto)antibodies. Thus, long-lived, autoreactive plasma cells are a relevant target for researchers aiming to develop curative therapies for autoimmune diseases.

Topics: Animals; Autoimmune Diseases; Bromodeoxyuridine; Chronic Disease; DNA; Female; Membrane Glycoproteins; Mice; Mice, Inbred NZB; Ovalbumin; Plasma Cells; Proteoglycans; Syndecans

TCR transgenic mice that express a peptide antigen in keratinocytes develop a lethal CD8 T cell-dependent autoimmune disease. We employed an adoptive transfer system to understand this disease and show that transfer of low numbers of naive CD8 T cells into peptide transgenic mice caused chronic skin disease. The antigen-presenting cell that initiated this response was the epidermal Langerhans cell. Naive CD8 T cells proliferated extensively, migrated to tissues, developed effector function, and were capable of making a recall response. These features are very different from the abortive activation of CD8 T cells that occurred in response to the same antigen presented by APC from other tissues. Furthermore, tolerance was dominant when the antigen was presented by both Langerhans cells and other APC. These data suggest that Langerhans cells do not have tolerogenic properties in the steady state.

Topics: Adoptive Transfer; Animals; Antigen Presentation; Autoantigens; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Cell Movement; Disease Models, Animal; Humans; Immune Tolerance; Keratin-14; Keratins; Langerhans Cells; Lymphocyte Activation; Mice; Mice, Transgenic; Ovalbumin; Promoter Regions, Genetic; Skin Diseases

Experimental autoimmune encephalomyelitis (EAE) is an animal model for multiple sclerosis (MS) characterized by chronic inflammatory demyelination of the central nervous system (CNS). The pathology of EAE involves autoimmune CD4(+) T(h)1 cells. There is a striking inverse correlation between the occurrence of parasitic and autoimmune diseases. We demonstrate that in mice with Schistosoma mansoni ova immunization, the severity of EAE is reduced as measured by decreased clinical scores and CNS cellular infiltrates. Disease suppression is associated with immune deviation in the periphery and the CNS, demonstrated by decreased IFN-gamma and increased IL-4, transforming growth factor-beta and IL-10 levels in the periphery, and increased frequency of IL-4 producing neuroantigen-specific T cells in the brain. S. mansoni helminth ova treatment influenced the course of EAE in wild-type mice, but not in STAT6-deficient animals. This indicates that STAT6 plays a critical role in regulating the ameliorating effect of S. mansoni ova treatment on the autoimmune response, and provides the direct link between helminth treatment, T(h)2 environment and improved EAE. As some intestinal helminthic infections induce minimal pathology, they might offer a safe and inexpensive therapy to prevent and/or ameliorate MS.

Topics: Animals; Autoimmune Diseases; Encephalomyelitis, Autoimmune, Experimental; Helminths; Immunization; Interleukin-4; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Models, Animal; Multiple Sclerosis; Ovalbumin; STAT6 Transcription Factor; Trans-Activators

To clarify the order of events occurring in the breakdown of the blood-retinal barrier (BRB) in experimental autoimmune uveoretinitis (EAU) and in particular to study the relationships between increased vascular permeability, upregulation of endothelial cell adhesion molecules, and leukocyte adhesion and infiltration during EAU.. B10.RIII mice were immunized with human interphotoreceptor retinoid binding protein (IRBP) peptide 161-180. Changes in the retinal microvasculature were examined on days 3, 6, 7, 8, 9, 10, 16, and 21 postimmunization (pi). Evans blue dye was administered intravenously to assess vascular permeability. Expression of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, P-selectin, E-selectin, and platelet endothelial cell adhesion molecule (PECAM)-1 was evaluated by in vivo administration of antibody and subsequent immunostaining of retinal wholemounts. Lymphocytes from inguinal lymph nodes of normal and chicken ovalbumin (OVA)- or IRBP peptide-immunized mice at day 5, 6, 7, 8, and 15 pi were labeled in vitro with calcein-AM (C-AM) and infused intravenously into syngeneic recipient mice, which had been immunized with peptide at the same corresponding time point. Wholemount preparations of retinas were observed 24 hours later by confocal microscopy to determine the adhesion and infiltration of lymphocytes.. The first observation of an increase in vascular permeability occurred at day 7 pi and was restricted to focal areas of the retinal postcapillary venules of the inner vascular plexus. This progressively extended to the outer vascular plexus at day 9 pi. Specific adhesion of leukocytes to the endothelium of retinal venules of the inner vascular plexus was first observed at day 6 pi. Leukocyte extravasation into the retinal parenchyma from these vessels began at day 8 pi and extended to the outer vascular plexus at day 9 pi. The expression of adhesion molecules increased progressively during the development of EAU. In particular, the adhesion molecules ICAM-1, P-selectin, and E-selectin were expressed predominately in retinal venules, the sites of BRB breakdown, cell adhesion, and extravasation, from day 7 pi. The increases in expression of ICAM-1 and P-selectin were associated both spatially and temporally with breakdown of the BRB, cell adhesion, and extravasation. No increase in expression of P-selectin and ICAM-1 was observed in either the mesenteric vessels of EAU mice or the retinal vessels of OVA-immunized mice.. The sequence of events in EAU appears to be focal adhesion of leukocytes to discrete sites on postcapillary venules, followed by upregulation of adhesion molecules, especially ICAM-1 and P-selectin, and breakdown of the BRB, leading to transendothelial migration of leukocytes and recruitment of large numbers of cells to the retinal parenchyma. These changes occur over a short period of 6 to 9 days pi and initiate the process of tissue damage during the following 2 to 3 weeks.

Topics: Animals; Autoimmune Diseases; Blood-Retinal Barrier; Capillary Permeability; Cell Adhesion; Cell Adhesion Molecules; Endothelium, Vascular; Eye Proteins; Female; Fluoresceins; Fluorescent Antibody Technique, Indirect; Fluorescent Dyes; Leukocytes; Mice; Microscopy, Confocal; Ovalbumin; Retinal Vessels; Retinol-Binding Proteins; Up-Regulation; Uveitis, Posterior

Antigen-specific suppression of a previously primed immune response is a major challenge for immunotherapy of autoimmune disease. RelB activation is required for myeloid DC differentiation. Here, we show that antigen-exposed DCs in which RelB function is inhibited lack cell surface CD40, prevent priming of immunity, and suppress previously primed immune responses. DCs generated from CD40-deficient mice similarly confer suppression. Regulatory CD4+ T cells induced by the DCs transfer antigen-specific "infectious" tolerance to primed recipients in an interleukin-10-dependent fashion. Thus CD40, regulated by RelB activity, determines the consequences of antigen presentation by myeloid DCs. These observations have significance for autoimmune immunotherapy and suggest a mechanism by which peripheral tolerance might be constitutively maintained by RelB(-) CD40(-) DCs.

Topics: Animals; Antigens; Autoimmune Diseases; CD4-Positive T-Lymphocytes; CD40 Antigens; Dendritic Cells; Hemocyanins; Immune Tolerance; Immunotherapy; Interferon-gamma; Interleukin-10; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Proto-Oncogene Proteins; Transcription Factor RelB; Transcription Factors

The addition of a foreign antigen to an inoculum completely inhibits the development of collagen-induced arthritis (CIA). However, the mechanism of this phenomenon, antigen -inhibition, is incompletely understood. Previous studies have demonstrated that the inhibition of arthritis is not mediated through suppression of the antibody response to cartilage antigens. In this paper we investigated cytokine mRNA levels in lymph nodes cells recovered 3, 7 or 16 days from animals immunized with either collagen II in IFA or OVA + collagen II in IFA. At day 7, but not at other time-points, IL-4 mRNA was up-regulated in the lymph nodes of OVA-inhibited non-arthritic animals compared to control animals which all developed arthritis. No significant differences between the two groups could be detected when expression of IFN-gamma, IL-2, TNF-alpha, IL-1beta or IL-10 mRNA was analysed. Flow cytometry analysis of draining lymph node cells demonstrated that the T cell marker Ox40 was up-regulated in the OVA-inhibited group. Our results indicate that the complete inhibition of CIA caused by addition of OVA to the collagen II inoculum is due to the presence of a TH2 environment resulting from an increased production of IL-4 mRNA and a parallel increase in Ox40+ T cells.

Topics: Animals; Antigens; Arthritis, Experimental; Autoimmune Diseases; Collagen; Cytokines; Female; Flow Cytometry; Freund's Adjuvant; Immunophenotyping; Interleukin-4; Lymph Nodes; Ovalbumin; Rats; Receptors, OX40; Receptors, Tumor Necrosis Factor; RNA, Messenger; Th2 Cells; Tumor Necrosis Factor Receptor Superfamily, Member 7; Up-Regulation

TRAIL, the tumor necrosis factor-related apoptosis-inducing ligand, selectively induces apoptosis of tumor cells, but not most normal cells. Its role in normal, nontransformed tissues is not clear. We report here that mice deficient in TRAIL have a severe defect in thymocyte apoptosis-thus, thymic deletion induced by T cell receptor ligation is severely impaired. TRAIL-deficient mice are also hypersensitive to collagen-induced arthritis and streptozotocin-induced diabetes and develop heightened autoimmune responses. Thus, TRAIL mediates thymocyte apoptosis and is important in the induction of autoimmune diseases.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Autoimmune Diseases; Cell Differentiation; Clonal Deletion; Collagen; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; T-Lymphocytes; Thymus Gland; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

Captopril, an angiotensin-converting enzyme inhibitor, is widely used in the treatment of a variety of cardiomyopathies, but its effect on autoimmune myocarditis has not been addressed experimentally. We investigated the effect of captopril on myosin-induced experimental autoimmune myocarditis. A/J mice, immunized with syngeneic cardiac myosin, were given 75 mg/L of captopril in their drinking water. Captopril dramatically reduced the incidence and severity of myocarditis, which was accompanied by a reduction in heart weight to body weight ratio and heart weight. Captopril specifically interfered with cell-mediated immunity as myosin delayed-type hypersensitivity (DTH) was reduced, while anti-myosin Ab production was not affected. Captopril-treated, OVA-immunized mice also exhibited a decrease in OVA DTH. In myosin-immunized, untreated mice, injection of captopril directly into the test site also suppressed myosin DTH. Interestingly, captopril did not directly affect Ag-specific T cell responsiveness because neither in vivo nor in vitro captopril treatment affected the proliferation, IFN-gamma secretion, or IL-2 secretion by Ag-stimulated cultured splenocytes. These results indicate that captopril ameliorates experimental autoimmune myocarditis and may act, at least in part, by interfering with the recruitment of cells to sites of inflammation and the local inflammatory environment.

Topics: Administration, Oral; Animals; Autoantibodies; Autoantigens; Autoimmune Diseases; Captopril; Cardiomegaly; Cell Division; Cells, Cultured; Cytokines; Epitopes, T-Lymphocyte; Hypersensitivity, Delayed; Injections, Subcutaneous; Male; Mice; Mice, Inbred A; Mice, Inbred BALB C; Mice, Transgenic; Myocarditis; Myosins; Ovalbumin; Peptidyl-Dipeptidase A; T-Lymphocyte Subsets; Up-Regulation

Using a previously described human keratin 14 (K14) promoter, we created mice expressing a peptide Ag (OVAp) in epithelial cells of the skin, tongue, esophagus, and thymus. Double transgenic mice that also express a TCR specific for this Ag (OT-I) showed evidence for Ag-driven receptor editing in the thymus. Surprisingly, such mice exhibited a severe autoimmune disease. In this work we describe the features of this disease and demonstrate that it is dependent on CD8 T cells. Consistent with the Ag expression pattern dictated by the human K14 promoter, an inflammatory infiltrate was observed in skin and esophagus and around bile ducts of the liver. We also observed a high level of TNF-alpha in the serum. Given that Ag expression in the thymus induced development of T cells with dual TCR reactivity, and that dual-reactive cells have been suggested to have autoimmune potential, we tested whether they were a causal factor in the disease observed here. We found that OT-I/K14-OVAp animals on a recombinase-activating gene-deficient background still suffered from disease. In addition, OT-I animals expressing OVA broadly in all tissues under a different promoter did not experience disease, despite having a similar number of dual-specific T cells. Thus, in this model it would appear that dual-reactive T cells do not underlie autoimmune pathology. Finally, we extended these observations to a second transgenic system involving 2C TCR-transgenic animals expressing the SIY peptide Ag with the hK14 promoter. We discuss the potential relationship between autoimmunity and self-Ags that are expressed in stratified epithelium.

Topics: Animals; Antigens; Autoimmune Diseases; CD8-Positive T-Lymphocytes; Egg Proteins; Epithelial Cells; Gene Expression; Genes, T-Cell Receptor; Humans; Keratin-14; Keratins; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; Peptide Fragments; Promoter Regions, Genetic; Receptors, Antigen, T-Cell, alpha-beta

Topics: Abatacept; Animals; Antigens, CD; Antigens, Differentiation; Autoantigens; Autoimmune Diseases; CD28 Antigens; Clonal Anergy; Clonal Deletion; CTLA-4 Antigen; Disease Models, Animal; Dose-Response Relationship, Immunologic; Gene Expression Regulation; Humans; Immunoconjugates; Immunotherapy; Interleukin-2; Mice; Ovalbumin; Self Tolerance; Time Factors

Links have been observed between infections and the development of autoimmunity. Proposed explanations include activation of self-Ag-bearing APC. Using a model system in which transgenic OVA is expressed in enterocytes, we showed that CD8 T cell recognition of cross-presented Ag in gut-associated lymph nodes was tolerogenic. However, concomitant infection with vesicular stomatitis virus encoding OVA abrogated tolerance and induced disease. We now show that following transfer of naive OT-I T cells, the addition of wild-type vesicular stomatitis virus, oral cholera toxin, or CD40 triggering can induce intestinal disease in transgenic mice. Tissue damage accompanied dramatic increases in cytokine release by activated OT-I cells in the intestine. The data indicated that products of antigenically unrelated infections can combine with cross-presented self-Ags on APC to prime autoaggressiveness, independent of additional Ag release. These results help explain how diverse pathogens, lacking any homology to self-proteins, could be causative agents in induction of organ-specific autoimmunity.

Topics: Adoptive Transfer; Animals; Autoantigens; Autoimmune Diseases; Cholera Toxin; Immune Tolerance; Inflammation; Intestinal Mucosa; Jejunum; Lymphocyte Transfusion; Mice; Mice, Inbred C57BL; Mice, Transgenic; Organ Specificity; Ovalbumin; Signal Transduction; Vesicular stomatitis Indiana virus

T cell receptor engagement and the B7-CD28 / CTLA-4 signaling pathways play critical roles in T cell activation and regulation. CD28 engagement results in T cell activation, differentiation and survival while CTLA-4 signals block IL-2 production, cell cycle progression and T cell differentiation. We explored the role of CTLA-4 in peripheral tolerance induced by intravenous administration of ethylene carbodiimide-fixed, antigen-coupled splenocytes in the PLP139 - 151-induced relapsing experimental autoimmune encephalomyelitis system. Tolerance induction with PLP139 - 151-coupled splenocytes correlates with low B7 expression on the fixed antigen-presenting cells, conditions that would favor CTLA-4-mediated inhibition. Administration of CTLA-4Ig or anti-CTLA-4 concomitant with the 'tolerogenic' stimulus, however, failed to reverse tolerance induction. In contrast, blocking CTLA-4 at the time of secondary 'immunogenic' encounter with antigen reversed the tolerant state. These findings indicate that CTLA-4 is required to maintain the unresponsive state of the tolerized T cells upon antigenic stimulation under inflammatory conditions and, therefore, have important implications for therapeutic regulation of autoimmune disease.

Topics: Abatacept; Amino Acid Sequence; Animals; Antigens, CD; Antigens, Differentiation; Autoantigens; Autoimmune Diseases; B7-1 Antigen; B7-2 Antigen; Capsid; Capsid Proteins; Cells, Cultured; Clonal Anergy; CTLA-4 Antigen; Encephalomyelitis, Autoimmune, Experimental; Female; Hypersensitivity, Delayed; Immune Tolerance; Immunization; Immunoconjugates; Inflammation; Lymphocyte Activation; Membrane Glycoproteins; Mice; Mice, Mutant Strains; Molecular Sequence Data; Myelin Basic Protein; Myelin Proteolipid Protein; Ovalbumin; Peptide Fragments; Receptors, Antigen, T-Cell; Specific Pathogen-Free Organisms; T-Lymphocyte Subsets; Thymectomy

Therapeutic use of recombinant human cytokines in humans can result in the generation of drug-specific antibodies. To predetermine the maximum potential effects of a granulocyte colony-stimulating factor (G-CSF) neutralizing auto-immunoglobulin G (auto-IgG) response during recombinant human G-CSF therapy, we developed a mouse model of mouse G-CSF (mG-CSF) neutralizing auto-IgG response. Mice were immunized and boosted with mG-CSF chemically conjugated to either keyhole limpet hemocyanin or ovalbumin on an alternating schedule. Sera were analyzed for mG-CSF-specific titers and full blood counts were performed on a Technicon H-1E. On day 252, tissues were collected for histology. IgG was protein A affinity purified from pooled mG-CSF autoimmune sera. Mice immunized with mG-CSF conjugates produced mG-CSF-specific auto-IgG responses that lasted for the length of the study. Significant neutropenia (p(max) < 0.004) was concurrent with the rise in mG-CSF-specific IgG titers. However, neutrophil counts remained at approximately 20% of preimmunization levels through day 252. Endogenous mG-CSF neutralizing auto-IgG had no significant effect on hemoglobin, erythrocyte, lymphocyte, eosinophil, basophil, and platelet counts, and had minor, transient, or no effects on monocyte counts. Bone marrow colony assays from mG-CSF autoimmune mice demonstrated no significant effect of G-CSF neutralization on the numbers or proliferative capacity of preneutrophil lineage progenitors. Purified IgG from mG-CSF autoimmune mice neutralized mG-CSF in vitro. High-titer G-CSF neutralizing auto-IgG in adult mice partially inhibited steady-state granulopoiesis and had little or no effect on steady-state levels of other hematopoietic cells.

Topics: Animals; Autoantibodies; Autoimmune Diseases; Colony-Forming Units Assay; Female; Granulocyte Colony-Stimulating Factor; Hematopoiesis; Hematopoietic Stem Cell Mobilization; Hemocyanins; Immunization; Immunoglobulin G; Mice; Models, Animal; Neutropenia; Ovalbumin; Recombinant Proteins; Reproducibility of Results; Specific Pathogen-Free Organisms

CD25(+)CD4(+) T cells are naturally occurring regulatory T cells that are anergic and have suppressive properties. Although they can be isolated from the spleens of normal mice, there are limited studies on how they can be activated or expanded in vivo. We found that oral administration of OVA to OVA TCR transgenic mice resulted in a modification of the ratio of CD25(+)CD4(+) to CD25(-)CD4(+) cells with an increase of CD25(+)CD4(+) T cells accompanied by a decrease of CD25(-)CD4(+) T cells. The relative increase in CD25(+)CD4(+) T cells persisted for as long as 4 wk post feeding. We also found that CTLA-4 was dominantly expressed in CD25(+)CD4(+) T cells and there was an increase in the percentage of CD25(+)CD4(+) T cells expressing CTLA-4 in OVA-fed mice. In contrast to CD25(-)CD4(+) cells, CD25(+)CD4(+) cells from fed mice proliferated only minimally to OVA or anti-CD3 and secreted IL-10 and elevated levels of TGF-beta(1) following anti-CD3 stimulation. CD25(+)CD4(+) cells from fed mice suppressed the proliferation of CD25(-)CD4(+) T cells in vitro more potently than CD25(+)CD4(+) T cells isolated from unfed mice, and this suppression was partially reversible by IL-10 soluble receptor or TGF-beta soluble receptor and high concentration of anti-CTLA-4. With anti-CD3 stimulation, CD25(+)CD4(+) cells from unfed mice secreted IFN-gamma, whereas CD25(+)CD4(+) cells from fed mice did not. Adoptive transfer of CD25(+)CD4(+) T cells from fed mice suppressed in vivo delayed-type hypersensitivity responses in BALB/c mice. These results demonstrate an Ag-specific in vivo method to activate CD25(+)CD4(+) regulatory T cells and suggest that they may be involved in oral tolerance.

Topics: Abatacept; Administration, Oral; Animals; Antigens; Antigens, CD; Antigens, Differentiation; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Clonal Anergy; CTLA-4 Antigen; Immune Tolerance; Immunoconjugates; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell; Receptors, Interleukin-2; T-Lymphocyte Subsets

Autoimmune gastritis, in which the H+/K(+)-ATPase of parietal cells is the major antigen, is one of the most common autoimmune diseases. Here we examined if specific properties of the H+/K(+)-ATPase or parietal cells are involved in rendering them autoimmune targets. The model antigens beta-galactosidase and ovalbumin (OVA) were expressed in parietal cells of transgenic mice. On experimental induction of autoimmune gastritis by neonatal thymectomy, autoantibodies to beta-galactosidase developed in mice expressing beta-galactosidase in parietal cells, a response that was independent of either the response to the gastric H+/K(+)-ATPase or gastric inflammation. In contrast, mice that expressed OVA in parietal cells did not exhibit an antibody response to OVA after thymectomy. However, increasing the frequency of anti-OVA T lymphocytes in OVA-expressing mice resulted in autoantibodies to OVA and gastritis. These studies indicate that parietal cells can present a variety of antigens to the immune system. Factors such as the identity and expression level of the autoantigen and the frequency of autoreactive T cells play a role in determining the prevalence and outcome of the particular immune response. In addition, as not all mice of a particular genotype displayed autoimmunity, random events are involved in determining the target of autoimmune recognition.

Topics: Animals; Autoantigens; Autoimmune Diseases; Autoimmunity; beta-Galactosidase; Female; Gastritis; Gene Expression; H(+)-K(+)-Exchanging ATPase; Immune Tolerance; Immunoglobulin G; Male; Mice; Mice, Transgenic; Ovalbumin; Parietal Cells, Gastric; Stomach; Thymus Gland; Transgenes

The use of altered peptide ligands (APL) with TCR antagonist properties holds promise as an antigen-specific therapy for autoimmune disorders. We are investigating the therapeutic potential of APL in experimental autoimmune encephalomyelitis (EAE) using the Ac1-9 peptide of myelin basic protein in H-2u mice. Encephalitogenic T cells recognize Ac1-9 using residues 3Gln and 6Pro as the major TCR contact sites. Use of position 6 APL is compromised by the heterogeneous nature of the Ac1-9-specific repertoire. Here we identify two position 3 APL that act as TCR antagonists on transgenic T cells expressing Ac1-9-specific TCR and that inhibit EAE in H-2u mice. However, the therapeutic capacity of these two APL correlated directly with the ability to maximally inhibit activation of a heterogeneous T cell pool. The implications of these findings for the requirements for EAE induction, the relative contribution of a given T cell subpopulation to pathology and the mechanism underlying EAE inhibition in this model are discussed.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; Autoimmunity; Encephalomyelitis, Autoimmune, Experimental; Immunodominant Epitopes; Immunotherapy; In Vitro Techniques; Mice; Mice, Transgenic; Molecular Sequence Data; Ovalbumin; Receptors, Antigen, T-Cell; T-Lymphocytes

To determine whether the inflammation of endotoxin-induced uveitis (EIU) and experimental autoimmune uveoretinitis (EAU) alters key in vivo and in vitro parameters of ocular immune privilege.. For EIU induction, C3H/HeN mice received 200 microg lipopolysaccharide (LPS). For EAU induction, B10.A mice were immunized with 50 microg interphotoreceptor retinoid-binding protein (IRBP) mixed with complete Freund's adjuvant. Aqueous humor (AqH) was collected at periodic intervals and assayed for leukocyte content and the ability to suppress or enhance T-cell proliferation. Eyes with EAU were assessed for the capacity to support anterior chamber (AC)-associated immune deviation (ACAID) induction after injection of ovalbumin (OVA).. Inflammation within the anterior segment in EIU peaked at 12 to 24 hours and was detected from 10 days onward in EAU. In AqH of EIU, protein content rose within 4 hours, followed by infiltrating leukocytes. EIU AqH promptly lost its capacity to suppress T-cell proliferation and became mitogenic for T cells. In AqH of EAU, protein and leukocyte content rose at 11 days and continued to remain elevated thereafter. Whereas 11-day EAU AqH failed to suppress T-cell proliferation, AqH at later time points reacquired immunosuppressive properties. Injection of OVA into the AC of eyes of mice with EAU failed to induce ACAID.. The intraocular inflammation of EIU and EAU disrupted important parameters of immune privilege, ranging from breakdown of the blood- ocular barrier, to loss of an immunosuppressive microenvironment, to abrogation of ACAID. Because AqH from inflamed EAU reacquired the ability to suppress T-cell proliferation, the authors conclude that the capacity to regulate immune expression and inflammation can be a property even of inflamed eyes.

Topics: Animals; Anterior Eye Segment; Aqueous Humor; Autoimmune Diseases; Blood-Aqueous Barrier; Eye Proteins; Hypersensitivity, Delayed; Inflammation; Leukocyte Count; Lipopolysaccharides; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Ovalbumin; Retinitis; Retinol-Binding Proteins; Salmonella typhimurium; T-Lymphocytes; Uveitis

The induction of apoptosis by death receptors serves to regulate immune responses by eliminating unwanted and harmful cells. Mature lymphocytes express FLICE inhibitory proteins (FLIPs) that block death receptor-induced cell death. Here, we show that both B and T cells downregulate c-FLIP upon activation in vitro. Retrovirus-mediated expression of c-FLIP blocks Fas-induced apoptosis of activated lymphocytes but does not affect cell death resulting from cytokine withdrawal. In vivo, c-FLIP expression results in defective superantigen-mediated elimination of T cells, the accumulation of activated B cells, the production of autoantibodies, and the development of autoimmune disease. No effect was seen on negative selection of thyomocytes. These results suggest that activation-dependent downregulation of c-FLIP renders mature lymphocytes sensitive to death receptor-mediated apoptosis and is required to maintain self-tolerance.

Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Carrier Proteins; CASP8 and FADD-Like Apoptosis Regulating Protein; Cells, Cultured; Down-Regulation; Enterotoxins; fas Receptor; Fas-Associated Death Domain Protein; Gene Expression; Genetic Vectors; Intracellular Signaling Peptides and Proteins; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Ovalbumin; Recombinant Fusion Proteins; Retroviridae; Staphylococcus aureus; Superantigens; T-Lymphocytes

Interest in oral tolerance has been renewed in the last few years as a possibility of intervention in human autoimmune diseases. An obstacle in this direction is that, although easily induced in animals virgin of contact with the antigen, oral tolerance becomes hard to induce in previously immunized animals. The present results show that there is an early period after primary immunization in which prolonged oral exposure to the antigen may arrest ongoing immune responses. Beyond this period, oral exposures to the antigen become ineffective and may actually boost immune responses. The end of the susceptible period coincides with the emergence of free specific antibodies in serum. However, the previous administration of purified anti-ovalbumin antibodies (40 micrograms) was unable to block the induction of oral tolerance to ovalbumin in normal mice.

Topics: Administration, Oral; Animals; Antibody Formation; Antigens; Autoimmune Diseases; Desensitization, Immunologic; Female; Immune Tolerance; Male; Mice; Ovalbumin; Time Factors

Although autoreactive T cells recognizing self myelin Ags are present in most individuals, autoimmune disease of the central nervous system is a relatively rare medical condition. Development of autoimmune disease may require not only the presence of autoreactive T cells but also that autoreactive T cells become activated. Activation of T cells may require a minimum of two signals: an Ag-specific signal delivered by MHC-peptide complex and a second signal delivered by costimulatory molecules or cytokines. Although in vitro studies have suggested that cytokines, especially proinflammatory cytokines such as IL-1, IL-6, and TNF are involved in T cell activation, their precise roles in vivo are not clear. To determine the roles of proinflammatory cytokines in T cell activation in vivo and in the development of autoimmune disease, we have studied experimental autoimmune encephalomyelitis (EAE) in mice deficient in IL-6. We found that IL-6-deficient mice were completely resistant to EAE induced by myelin oligodendrocyte glycoprotein (MOG), whereas IL-6-competent control mice developed EAE characterized by focal inflammation and demyelination in the central nervous system and deficiency in neurologic functions. Furthermore, we established that the resistance to EAE in IL-6-deficient mice was associated with a deficiency of MOG-specific T cells to differentiate into either Th1 or Th2 type effector cells in vivo. These results strongly suggest that IL-6 plays a crucial role in the activation and differentiation of autoreactive T cells in vivo and that blocking IL-6 function can be an effective means to prevent EAE.

Topics: Animals; Autoimmune Diseases; Autoimmunity; Cell Differentiation; Concanavalin A; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Immunity, Innate; Immunization; Interleukin-6; Lymphocyte Activation; Mice; Mice, Knockout; Myelin Proteins; Myelin-Associated Glycoprotein; Myelin-Oligodendrocyte Glycoprotein; Ovalbumin; T-Lymphocyte Subsets

Many T cells with auto-aggressive potential are deleted in the thymus. Although some of these escape to the general circulation, they do not usually damage organs such as the pancreas. To investigate the mechanisms preventing autoimmunity, we generated transgenic mice expressing known genes under the control of various promoters. We found that the occurrence of autoaggression depended on factors such as the precursor frequency of responding T cells, their state of activation, their accessibility to the autoantigen, the physicochemical properties of the autoantigen, the possibility of priming by environmental antigens which mimic the target antigen, and some inflammatory reaction in the target site.

Topics: Animals; Autoimmune Diseases; Autoimmunity; Diabetes Mellitus, Experimental; H-2 Antigens; Immune Tolerance; Islets of Langerhans; Metallothionein; Mice; Mice, Transgenic; Ovalbumin; Promoter Regions, Genetic; T-Lymphocytes; Thymus Gland

The induction of T cell anergy in vivo is thought to result from antigen recognition in the absence of co-stimulation and inflammation, and is associated with a block in T cell proliferation and Th1 differentiation. Here we have examined the role of interleukin (IL)-12, a potent inducer of Th1 responses, in regulating this process. T cell tolerance was induced by the administration of protein antigen without adjuvant in normal mice, and in recipients of adoptively transferred T cells from T cell receptor transgenic mice. The administration of IL-12 at the time of tolerance induction stimulates Th1 differentiation, but does not promote antigen-specific T cell proliferation. Conversely, inhibiting CTLA-4 engagement during anergy induction reverses the block in T cell proliferation, but does not promote full Th1 differentiation. T cells exposed to tolerogenic antigen in the presence of both IL-12 and anti-CTLA-4 antibody are not anergized, and behave identically to T cells which have encountered immunogenic antigen. These results suggest that two processes contribute to the induction of anergy in vivo; CTLA-4 engagement, which leads to a block in the ability of T cells to proliferate to antigen, and the absence of a prototypic inflammatory cytokine, IL-12, which prevents the differentiation of T cells into Th1 effector cells. The combination of IL-12 and anti-CTLA-4 antibody is sufficient to convert a normally tolerogenic stimulus to an immunogenic one.

Topics: Abatacept; Adoptive Transfer; Animals; Antibodies; Antigens, CD; Antigens, Differentiation; Autoimmune Diseases; Cell Differentiation; Clonal Anergy; CTLA-4 Antigen; Flow Cytometry; Immune Tolerance; Immunoconjugates; Inflammation; Interferon-gamma; Interleukin-12; Mice; Mice, Inbred BALB C; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell; T-Lymphocytes; Th1 Cells

The thyroiditogenic T cell receptor (TCR) repertoire is not yet well defined in murine experimental autoimmune thyroiditis (EAT). Our recent work has shown that, while V beta 8+ T cells have no major role in EAT induction with mouse thyroglobulin (MTg), V beta 13 may be involved. To examine the effect of skewing the TCR repertoire on EAT development, CBA (H2k) mice were mated with B10.Q mice harboring an ovalbumin-specific V beta 8.2 TCR transgene (trg), and the trg+ mice were backcrossed to CBA. FACS analysis showed that peripheral blood T cells from trg+ mice had about 76 and 90% V beta 8.2+ cells in the CD4+ and CD8+ subsets, respectively, compared with about 15 and 11% in trg- sibs. The transgenic CBA k/k and k/q mice were immunized with MTg and sacrificed 28 days later. In all trg+ mice, anti-MTg titers and T cell proliferative responses to MTg were significantly lowered. However, thyroid infiltration was distinctly different in the two strains of transgenic mice; a significant decrease was seen primarily in k/q, but not k/k, trg+ mice. Thus, skewing the TCR repertoire to overexpress an irrelevant TCR revealed the possession of a less flexible thyroiditogenic TCR repertoire in k/q, but not k/k, mice.

Topics: Animals; Autoimmune Diseases; Cells, Cultured; Disease Models, Animal; Gene Expression; Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; H-2 Antigens; Histocompatibility Antigens Class II; Immunization; Lymphocyte Activation; Mice; Mice, Inbred CBA; Mice, Transgenic; Ovalbumin; Protein Multimerization; Receptors, Antigen, T-Cell, alpha-beta; Species Specificity; Specific Pathogen-Free Organisms; Spleen; T-Lymphocyte Subsets; Thyroglobulin; Thyroiditis, Autoimmune; Transgenes

An antigen administered orally can induce immunological tolerance to a subsequent challenge with the same antigen. Evidence has been provided for the efficacy of this approach in the treatment of human autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. However, oral administration of autoantigen in mice was found to induce a cytotoxic T lymphocyte response that could lead to the onset of autoimmune diabetes. Thus, feeding autoantigen can cause autoimmunity, which suggests that caution should be used when applying this approach to the treatment of human autoimmune diseases.

Topics: Administration, Oral; Animals; Autoantigens; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Chimera; Diabetes Mellitus; Dose-Response Relationship, Immunologic; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; T-Lymphocytes, Cytotoxic

Topics: Animals; Antigens; Autoimmune Diseases; Callithrix; CD8-Positive T-Lymphocytes; Cytokines; Diabetes Mellitus, Type 1; Encephalomyelitis, Autoimmune, Experimental; Humans; Immune Tolerance; Immunotherapy; Mice; Myelin Proteins; Myelin-Associated Glycoprotein; Myelin-Oligodendrocyte Glycoprotein; Ovalbumin; Th1 Cells; Th2 Cells

Previous studies have illustrated the importance of T cells bearing alpha beta TCRs in the induction and development of collagen induced arthritis (CIA) in mice. However, the scope of TCR usage in CIA has yet to be clearly defined. Given the inherent diversity of the TCR repertoire, the relative flexibility of the arthritogenic TCR repertoire specific for type II collagen (CII) is not clear. Therefore, we chose to examine the influence of a highly skewed TCR repertoire on CIA. Arthritis susceptible B10.Q (H-2q) mice were mated with C57L (H-2b) animals expressing an ovalbumin-specific V beta 8.2 TCR transgene (Tg) and Tg+ offspring were further backcrossed to B10.Q. Homozygous H-2q/q, V beta 8.2 Tg+ mice displayed a high level of V beta 8.2+ T cells in peripheral blood. However, expression of some endogenous V beta TCR, such as V beta 14, was still detected. Upon immunization with bovine CII in adjuvant, V beta 8.2 Tg+ mice were highly resistant to CIA when compared with Tg- littermates. Analysis of sera demonstrated a marked reduction in antibody specific for homologous mouse CII as well as heterologous bovine CII in Tg+ animals. Interestingly, V beta 8.2 Tg+ mice still mounted good antibody responses following immunization with human thyroglobulin, indicating that the skewed TCR repertoire affected anti-CII but not antithyroglobulin responses. Thus, our findings show that constraints placed on the TCR repertoire inhibit pathogenic responses against CII and suggest that in H-2q mice the arthritogenic TCR repertoire bears only limited flexibility.

Topics: Animals; Arthritis, Experimental; Autoimmune Diseases; Collagen; Epitopes; Gene Expression Regulation; Immunity, Innate; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell, alpha-beta

We previously reported that immunity to the p277 peptide of the human 60-kDa heat shock protein (hsp60) was a causal factor in the diabetes of non-obese diabetic (NOD) mice, which are genetically prone to develop spontaneous autoimmune diabetes. The present study was done to test whether immunization with the p277 peptide could cause diabetes in standard strains of mice. We now report that a single administration of the p277 peptide conjugated to carrier molecules such as bovine serum albumin or ovalbumin can induce diabetes in C57BL/6 mice and in other strains not genetically prone to develop diabetes. The diabetes was marked by hyperglycemia, insulitis, insulin autoantibodies, glucose intolerance and low blood levels of insulin. The diabetes could be transferred to naive recipients by anti-p277 T cell lines. Similar to other experimentally induced autoimmune diseases, the autoimmune diabetes remitted spontaneously. After recovery, the mice were found to have acquired resistance to a second induction of diabetes. Susceptibility to induced diabetes in C57BL/6 mice was influenced by sex (males were much more susceptible than were females) and by class II genes in the major histocompatibility complex (B6.H-2bm12 mice with a mutation in the MHC-II molecule were relatively resistant). Other strains of mice susceptible to induced diabetes were C57BL/KSJ, C3HeB/FeJ, and NON/Lt. BALB/c and C3H/HeJ strains were relatively resistant. Immunization to p277-carrier conjugates could also induce transient hyperglycemia in young NOD mice, but upon recovery from the induced diabetes, the NOD mice were found to have acquired resistance to later development of spontaneous diabetes. Thus, T cell immunity to the p277 peptide can suffice to induce diabetes in standard mice, and a short bout of induced diabetes can affect the chronic process that would otherwise lead to spontaneous diabetes in diabetes-prone NOD mice.

Topics: Amino Acid Sequence; Animals; Autoantibodies; Autoimmune Diseases; Blood Glucose; Cattle; Chaperonin 60; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Disease Susceptibility; Female; Genes, MHC Class II; Glucose Tolerance Test; Humans; Immunization; Immunotherapy, Adoptive; Insulin; Islets of Langerhans; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred NOD; Molecular Sequence Data; Ovalbumin; Peptide Fragments; Receptors, Interleukin-1; Serum Albumin, Bovine; Species Specificity; T-Lymphocytes

Topics: Animals; Arthritis, Experimental; Autoimmune Diseases; Collagen; Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; H-2 Antigens; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell, alpha-beta; T-Lymphocytes

Oral administration of retinal soluble antigen (S-Ag) suppresses the induction of S-Ag-mediated experimental autoimmune uveitis (EAU) in Lewis rats. EAU induced with interphotoreceptor retinoid-binding protein (IRBP), another retinal autoantigen, can also be suppressed by oral administration of IRBP. It has been speculated that feeding with one retinal autoantigen could suppress induction of uveitis with the other retinal protein by means of bystander suppression. Both uveitogenic effector and suppressor cells should find their antigens within the retina, where the suppressor cells would be expected to act on the effector cells. However, reciprocal combinations of antigens used for induction and suppression of uveitis failed to prevent onset of disease, demonstrating that bystander suppression obviously does not occur in the eye. To investigate further the localization of suppressor mechanisms, we fed Lewis rats either with retinal S-Ag or with ovalbumin (OVA) and then immunized the animals either with a mixture of S-Ag and OVA or with each antigen separately, injected into contralateral hind legs. Feeding of S-Ag prior to immunization led to suppression of uveitis, whereas feeding of OVA had no tolerizing effect when S-Ag and OVA were injected into different legs. Nevertheless, immunizing rats with a mixture of S-Ag and OVA after OVA feeding suppressed uveitis to a high degree. These findings suggest that orally induced bystander suppression might not occur in the target organ, but rather peripherally at the site of induction of the autoimmune T cells.

Topics: Administration, Oral; Animals; Anterior Chamber; Antigens; Arrestin; Autoimmune Diseases; Cells, Cultured; Desensitization, Immunologic; Eye; Eye Proteins; Hindlimb; Immune Tolerance; Immunization; Injections, Subcutaneous; Lymph Nodes; Lymphocyte Activation; Ovalbumin; Rats; Rats, Inbred Lew; Retinitis; Retinol-Binding Proteins; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory; Tail; Uveitis

We used synthetic peptides to analyze the human natural antibody response to V beta determinants. A major determinant recognized by IgM and IgG autoantibodies of clinically healthy individuals as well as those suffering from rheumatoid arthritis (RA) was a peptide corresponding to the first complementarity-determining region (CDR1). The natural IgM response of RA patients to this synthetic autoepitope was significantly elevated relative to that shown by healthy individuals. The levels of IgM reactivity to determinants corresponding to this region decreased with increasing age. By contrast, IgG autoantibodies to certain V beta CDR1 peptides increased markedly with age. In order to determine whether the CDR1 V beta determinant might be involved in immunization, we immunized rabbits with a human peptide that is greater than 80% identical to the homologous sequence derived from a rabbit V beta gene. As a control, the rabbits were immunized with a peptide of equal length derived from the N-terminus of the human V beta chain. Like humans, rabbits tended to have high levels of autoantibodies to the CDR1 peptide but not to the N-terminal segment. Following immunization, the rabbits produced strong IgG responses to the N-terminal peptide. By contrast, immunization with the CDR1 peptide resulted in levels of IgG antibody less than or equal to the natural activity in unimmunized rabbits. These studies indicate that the CDR1 region of Tcr V beta is a widely recognized autoantigenic portion of the Tcr that most probably functions as a regulatory epitope in man and other species.

Topics: Adult; Aged; Aged, 80 and over; Aging; Amino Acid Sequence; Arthritis, Rheumatoid; Autoantibodies; Autoimmune Diseases; Dose-Response Relationship, Immunologic; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Immunoglobulin M; Immunoglobulin Variable Region; Immunoglobulins, Intravenous; Lupus Erythematosus, Systemic; Male; Middle Aged; Molecular Sequence Data; Ovalbumin; Receptors, Antigen, T-Cell, alpha-beta; Sequence Alignment; Sequence Homology, Amino Acid

We compared the time course of changes in serum levels of circulating immune complexes (CICs) and of IgG antibody after sensitization of albino Lewis and pigmented Lister strain rats with uveitogenic (retinal S-antigen) and non-uveitogenic (ovalbumin) protein antigens of comparable molecular weight. Normal levels of CICs were far lower in Lewis rats in which experimental autoimmune uveoretinitis (EAU) takes the form of a severe panuveitis, than in Lister rats, in which the disease is mild, focal, confined to the posterior segment, and of lower incidence. After sensitization with either S-antigen or ovalbumin, polyethylene-glycol-precipitable CIC (PEG-CIC) peaked and fell as IgG antibody levels rose in both rat strains. However, peak levels of PEG-CIC were lower and subsequent IgG antibody levels were higher in the Lewis strain than in the less susceptible Lister strain. In both strains of rat these linked PEG-CIC/IgG antibody responses occurred earlier after sensitization with uveitogenic (S-) antigen than with ovalbumin, whether or not individual S-antigen-sensitized Lister rats developed EAU. In contrast, complement-binding CIC rose substantially only in those rats of both strains displaying EAU in response to S-antigen and not in response to ovalbumin. We suggest that immune complex (idiotypic) regulation of IgG antibody responses may be more readily perturbed by a pathogenic autoantigen (S-antigen) than by a bland antigen (ovalbumin). We also suggest that differences between the balance of regulatory and pathogenic CIC responses to uveitogenic retinal antigen may underlie or reflect strain differences in susceptibility to and severity of EAU.

Topics: Animals; Antigen-Antibody Complex; Antigens; Arrestin; Autoimmune Diseases; Enzyme-Linked Immunosorbent Assay; Eye Proteins; Freund's Adjuvant; Immunoglobulin G; Male; Ovalbumin; Rats; Rats, Inbred Lew; Retinitis; Species Specificity; Uveitis

Splenic T cells from myelin basic protein (MBP)-immunised Lewis rats were activated to transfer experimental autoimmune encephalomyelitis (EAE) by co-culture with MBP-pulsed lymphoid dendritic cells (DC). MBP-pulsed DC could be kept for at least 24 h at 37 degrees C in antigen-free medium without affecting their ability subsequently to activate encephalitogenic T cells. However, MBP-pulsed DC were rendered much less stimulatory after a 6 h, but not 2 h, secondary incubation with ovalbumin. Thus, although encephalitogenic complexes between MBP and DC appear very stable in the absence of competing antigens, in their presence, antigen exchange can take place over a period of a few hours; this has positive implications for therapy of EAE by antigen competition.

Topics: Animals; Antigen-Presenting Cells; Autoimmune Diseases; Binding, Competitive; Cell Communication; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Myelin Basic Protein; Ovalbumin; Rats; Rats, Inbred Lew; Spleen; T-Lymphocytes

We have evaluated the antibody and the effector T-cell responses to a single cerebrospinal fluid (CSF) infusion of myelin basic protein (MBP) in Lewis rats by measuring serum anti-MBP antibodies and clinical signs of experimental autoimmune encephalomyelitis (EAE), respectively. Some rats developed anti-MBP antibodies, but none manifested EAE in response to the primary infusion. Antibody responses to an EAE challenge 3 weeks after CSF infusion were normal, but clinical symptoms of EAE were markedly suppressed. Brain trauma at the time of MBP pretreatment enhanced this suppression. The CSF route of MBP administration is more effective in inducing suppression of EAE than peripheral routes.

Topics: Animals; Antibody Formation; Autoimmune Diseases; Encephalomyelitis, Autoimmune, Experimental; Epitopes; Injections, Intraventricular; Male; Myelin Basic Protein; Ovalbumin; Rats

Polyclonal B cell activation is an early feature of autoimmune disease in humans and mice with systemic lupus erythematosus. The contribution of polyclonal activation to the progression of autoimmunity is unclear, however, since it precedes the development of end-organ damage by months or years. To examine this issue, 109 autoimmune-prone (NZB X NZW)F1 X NZB backcross mice were hemi-splenectomized at 10 wk and the number and antigenic specificity of their Ig-secreting B cells quantitated by ELISA spot assay. Of the 61 mice that had polyclonally increased numbers of Ig-secreting cells/spleen, 31 died by 6 mo. In contrast, 0/48 backcross mice with normal numbers of Ig-secreting B cells at 10 wk died over the same period (P less than 0.001). Polyclonally activated mice also developed proteinuria earlier and more frequently than littermates with normal numbers of Ig-secreting cells (P less than 0.001). As adults, backcross mice with proteinuria expressed repertoires skewed towards the production of anti-DNA antibodies. At 10 wk these same mice expressed repertoires marked by polyclonal activation rather than preferential anti-DNA production. These findings indicate that autoimmune disease in SLE is accompanied by the autoantigen-driven production of autoantibodies but is preceded and predicted by polyclonal B cell activation.

Topics: Animals; Autoantibodies; Autoimmune Diseases; B-Lymphocytes; DNA; Immunoglobulins; Lupus Nephritis; Lymphocyte Activation; Mice; Mice, Inbred Strains; Ovalbumin

The processes responsible for the production of autoantibodies have been shown to include both Ag-specific and generalized (polyclonal) forms of B cell activation. The relative contribution and temporal association of these processes to the genesis of systemic autoimmunity are incompletely understood. To study this relationship, the B cell repertoires of MRL-lpr/lpr mice were analyzed by ELISA spot assay over an 8-mo period. Between 6 and 12 wk of age, the number of splenic lymphocytes producing antibodies reactive with both autoantigens and conventional Ag increased proportionately. The repertoires of MRL-lpr/lpr mice under 12 wk were dominated by IgM-secreting B cells that showed no bias toward the production of specific autoantibodies. From 12 to 38 wk of age, an increasing proportion of animals developed repertoires dominated by IgG-secreting B cells that were skewed toward reactivity against one or very few (auto)antigens. Although there was no single Ag against which all mice developed skewed reactivity, 55% of MRL-lpr/lpr adults had increased numbers of B cells producing antibodies to the Sm Ag and 13 to 16% developed increased reactivity toward DNA, myosin, histone, thyroglobulin, or T cells. These data indicate that generalized (polyclonal) B cell activation dominates early repertoire development whereas (auto)-antigen-specific responses become increasingly important during the latter stages of disease in these autoimmune-prone mice.

Topics: Age Factors; Animals; Antibody-Producing Cells; Autoantibodies; Autoantigens; Autoimmune Diseases; B-Lymphocytes; DNA; Hemocyanins; Immunoglobulin G; Immunoglobulin Isotypes; Immunoglobulin M; Leukocyte Count; Lymphocyte Activation; Mice; Mice, Mutant Strains; Myosins; Ovalbumin; Ribonucleoproteins, Small Nuclear; snRNP Core Proteins

Advances in our understanding of the structure and molecular biology of the T lymphocyte antigen-receptor have now made it feasible to study human autoimmune diseases using new approaches. One such approach involves cloning of T cells from sites of autoimmune pathology followed by identification of putative disease-related T cell oligoclonality at the level of the T cell receptor gene rearrangements. We have now tested the feasibility of this approach in an animal model of autoimmunity, murine experimental allergic encephalomyelitis (EAE). Spinal cord-derived, self (murine) myelin basic protein (MBP)-reactive T cell lines and sublines were analyzed at the level of their receptor beta chain rearrangements using Southern blots. We now report that the MBP-reactive T cell lines and sublines derived from the spinal cords of four of five SJL/J mice with EAE share a 14.5-kb rearranged T cell receptor beta 1 band on Southern blots. A spinal cord-derived T cell line that was reactive to purified protein derivative of tuberculin (PPD), several lymph node-derived ovalbumin- and PPD-reactive T cell lines, as well as one MBP-reactive spinal cord-derived T cell line did not share this 14.5-kb rearranged beta 1 band. These results suggest that analysis of the antigen receptors used by T cells cloned from sites of inflammation may be a useful initial approach for identifying pathogenetically relevant T cells in the study of certain human autoimmune diseases.

Topics: Animals; Autoimmune Diseases; Autoradiography; Cell Line; Cloning, Molecular; Deoxyribonuclease HindIII; Disease Models, Animal; DNA; DNA Restriction Enzymes; Encephalomyelitis, Autoimmune, Experimental; Lymphocyte Activation; Male; Mice; Myelin Basic Protein; Nucleic Acid Hybridization; Ovalbumin; Receptors, Antigen, T-Cell; Spinal Cord; T-Lymphocytes; Tuberculin

Previous work from this laboratory has revealed that spleen and/or lymph node cells from Lewis rats, that have recovered from an acute episode of experimental autoimmune encephalomyelitis (EAE), suppress the development of EAE when injected into syngeneic recipients subsequently challenged with myelin basic protein (MBP) in CFA. In an effort to understand the mechanism of this suppression, we measured the production of immune IFN-gamma, which may be required for the induction of an immune response, by EAE effector T cells (which transfer disease) and EAE suppressor cells when cultured in vitro with MBP. We now report that EAE effector T cells produce IFN-gamma when cultured in vitro with MBP. In contrast, spleen cells from recovered rats (which manifest suppressor activity in vivo) do not produce IFN-gamma. Moreover, in cell mixing experiments, these suppressor spleen cells inhibited the production of IFN-gamma by EAE effector cells. This inhibition was not eliminated by the removal of macrophages nor by the inhibition of PG synthesis by indomethacin. Furthermore, the inhibition was shown to be Ag-specific and mediated by nylon-adherent, radiation-sensitive splenic T cells. The findings suggest that suppressor cells regulate EAE by inhibiting IFN-gamma production by effector cells. This inhibition may result in the down-regulation of IFN-gamma-induced expression of class II major histocompatibility Ag on cells of the central nervous system, thus reducing the presentation of tissue-specific Ag (i.e., MBP) to autoreactive lymphocytes.

Topics: Acute Disease; Animals; Antigens; Autoimmune Diseases; Encephalomyelitis, Autoimmune, Experimental; Female; Immunization, Passive; Interferon-gamma; Ovalbumin; Rats; Rats, Inbred Lew; T-Lymphocytes; T-Lymphocytes, Regulatory

Egg-induced granuloma formation in murine schistosomiasis mansoni results from vigorous anti-parasite reaction by activated T cells, macrophages, eosinophils, and fibroblasts. The present study suggests that strain-specific, autoimmune T-cell reactivity directed against host matrix proteins might also contribute to granulomatous hypersensitivity. T cells from infected C57B1/6, but not from CBA or BALB/c mice, proliferative in vitro in response to denatured collagen. T cells from uninfected mice, previously immunized with soluble egg antigen (SEA), did not respond in vitro to collagen. Spleen cells from acutely infected mice, but not chronically infected or uninfected animals, formed granulomas around collagen-coupled polyacrylamide beads in vitro. This response was blocked by anti-collagen antibodies that had no inhibitory effect on in vitro granuloma formation around SEA-coupled beads. In related in vivo studies, granuloma formation was quantitated after iv injection of SEA-, collagen-, or uncoated beads into normal or infected recipients. The mean diameter of lung granulomas induced by collagen-coupled beads in infected mice was significantly greater than the diameter of granulomas around either collagen beads in uninfected mice or uncoated beads in infected mice. these observations indicate that anti-collagen responses develop spontaneously in Schistosoma-infected mice and suggest that such reactivity might play a secondary role in granuloma formation and the pathogenesis of hepatic fibrosis.

Topics: Animals; Autoimmune Diseases; Collagen; Female; Granuloma; Lymph Nodes; Lymphocyte Activation; Mice; Ovalbumin; Peritoneal Cavity; Schistosomiasis mansoni; T-Lymphocytes

Daunomycin, when conjugated with a targeting antigen by an acid-sensitive spacer, remains inactive at the intravascular pH of 7 but becomes active after cleavage within the acidic lysosomal environment of the target cell. This observation made it possible to construct cytocidal compounds that caused antigen-specific suppression of murine lymphocyte function. When daunomycin was coupled to the hapten conjugate of ovalbumin by an acid-sensitive cis-aconityl group, it caused hapten-specific impairment of immunocompetence in murine B lymphocytes in vitro and in vivo. Furthermore, the response by T lymphocytes to concanavalin A in vitro was selectively eliminated by a conjugate between daunomycin plus the acid-sensitive spacer and a monoclonal antibody specific for T cells.

Topics: Animals; Autoimmune Diseases; Concanavalin A; Daunorubicin; Fluorescein; Fluoresceins; Immunosuppression Therapy; Immunosuppressive Agents; Lymphocyte Activation; Mice; Mice, Inbred CBA; Nitrohydroxyiodophenylacetate; Ovalbumin; Picrates; Spleen; T-Lymphocytes

Topics: Animals; Antibody Formation; Autoimmune Diseases; B-Lymphocytes; gamma-Globulins; Immune Tolerance; Immunologic Memory; Interleukin-2; Ovalbumin; T-Lymphocytes; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory

Three strains of mice, BXSB, MRL-lpr/lpr, and NZB, which spontaneously develop autoimmune syndromes, all fail to become tolerant to challenge with bovine gamma-globulin (BGG) in adjuvant by prior intraperitoneal (ip) injection of BGG in tolerogenic form. In the present study, these three strains were examined for the ability of a single enteric dose of BGG or ovalbumin (OVA) to tolerize to subsequent challenge with the corresponding antigen in adjuvant. In contrast to lack of ip tolerance to BGG, BXSB mice were tolerant to gastrointestinal (GI) BGG as well as to GI OVA, suggesting that ip and GI forms of tolerance to BGG operate through distinct mechanisms in these mice. MRL-lpr/lpr mice had normal tolerance to GI OVA but not GI BGG. The presence of enteric tolerance to one antigen but not another suggests that the responsible cellular defects vary from one antigen to another. NZB mice lacked tolerance to both GI BGG and GI OVA. Splenectomy of NZB mice allowed normal tolerance to enteric BGG; spleen cells administered to splenectomized NZB mice interfered with BGG tolerance. Congenic NZB.xid mice were tolerant only to OVA. These results suggest that in NZB mice Lyb 5+ cells interfere with tolerance to enteric OVA and Lyb 5- spleen cells interfere with tolerance to enteric BGG.

Topics: Animals; Antibody Formation; Antigens; Autoimmune Diseases; Female; gamma-Globulins; Genes, Regulator; Immune Tolerance; Immunization, Passive; Intubation, Gastrointestinal; Male; Mice; Mice, Inbred DBA; Mice, Inbred NZB; Mice, Mutant Strains; Ovalbumin; Splenectomy

To determine whether the existence of anti-dsDNA producing lymphocyte clones is limited to autoimmune strains of mice, spleen cells derived from autoimmune mice (NZB, NZB X NZW F1, MRL) and from normal strains (BALB/c, DBA/2, C57BL/6, C3H/eb) were cultured with E. coli lipopolysaccharide (LPS). DNase-treated supernatants from these cultures were assayed for anti-dsDNA antibodies by employing a sensitive solid-phase radioimmunoassay with poly (dA-dT) as the antigen. All tested spleen cells secreted a small yet significant amount of anti-dsDNA upon stimulation with LPS. There was no difference in the amount or in the heavy chain type of anti-dsDNA secreted by cells from normal and autoimmune strain cells. Evidence of clonal expansion in unstimulated cells was observed only in cultures prepared from older autoimmune animals. Removal of T cells from the spleen cell preparations had no marked effect on the spontaneous or stimulated antibody secretion. Anti-dsDNA antibodies could also be induced in vivo by i.p. injection of LPS into young normal animals. Splenocytes from all tested strains spontaneously secreted anti-ssDNA and anti-TNP antibodies in culture, and these were present at relatively high levels in the serum of unstimulated animals. Stimulation with LPS increased secretion of anti-ssDNA and anti-TNP in all strains in vitro and in five of seven strains in vivo as well. It can be concluded that a) the existence of anti-dsDNA-producing clones is not limited to autoimmune strains, and b) these clones are expanded in old but not in young autoimmune mice. They are not expanded in normal mice at any age.

Topics: Aging; Animals; Antibodies; Autoimmune Diseases; Cattle; Cells, Cultured; DNA; Female; Immunoglobulin G; Immunoglobulin M; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Inbred NZB; Mitogens; Ovalbumin; Spleen; T-Lymphocytes

Topics: Aging; Animals; Antibody Formation; Autoimmune Diseases; B-Lymphocytes; Dinitrobenzenes; Epitopes; Female; Hemocyanins; Immunization, Passive; Immunoglobulin E; Immunoglobulin G; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred NZB; Ovalbumin; T-Lymphocytes; Time Factors

The effects of antigenic competition between ovalbumin and sperm autoantigens have been studied in guinea pigs. There was an inhibition of antiovalbumin antibody production up to 60 days after immunization. The cell-mediated immunity against ovalbumin was also depressed at day 30. The simultaneous immunization with both antigens has no effect upon the humoral and cell-mediated immunity against spermatozoa. During the period of inhibition of the humoral and cell-mediated antiovalbumin response, the number of animals developing autoimmune aspermatogenic orchitis was diminished compared to those immunized with spermatozoa alone. Later on, there was no difference between the two groups. The transient inhibition of the immune response against ovalbumin can be explained by the particulate nature of the autoantigens. The sperm cells may be easily trapped by the dendritic reticular cells of the draining lymph nodes. This in turn could affect T cell recognition at early stages, orienting it predominantly toward the sperm autoantigens. At day 90 the situation returned to that present in animals immunized with ovalbumin alone.

Topics: Animals; Antibody Formation; Antigen-Antibody Reactions; Autoimmune Diseases; Cell Migration Inhibition; Guinea Pigs; Immunity, Cellular; Immunization; Lymphocyte Activation; Macrophages; Male; Orchitis; Ovalbumin; Spermatozoa; Testis

Topics: Adjuvants, Immunologic; Animals; Antibody Formation; Arthus Reaction; Autoantigens; Autoimmune Diseases; Freund's Adjuvant; Guinea Pigs; Hemagglutination Tests; Hypersensitivity, Delayed; Injections, Intradermal; Male; Mycobacterium; Ovalbumin; Spermatozoa; Testis

Topics: Animals; Autoimmune Diseases; Guinea Pigs; Hemadsorption; Hemagglutination Tests; Hemocyanins; Immune Sera; Immunization; Immunization, Passive; Kidney; Liver; Mollusca; Ovalbumin; Rabbits; Skin Tests; Thyroglobulin; Thyroid Gland; Thyroiditis; Tissue Extracts

Topics: Animals; Autoimmune Diseases; Carcinogens; Guinea Pigs; Hypersensitivity, Delayed; Hypersensitivity, Immediate; Immunity; Immunosuppression Therapy; Lymphocytes; Male; Methotrexate; Methylcholanthrene; Nitrosamines; Ovalbumin; Testis; Time Factors; Tuberculin Test

Topics: Animals; Antibodies, Anti-Idiotypic; Antigen-Antibody Reactions; Autoimmune Diseases; Complement Fixation Tests; Disease Models, Animal; Female; Hemagglutination Tests; Hypersensitivity, Immediate; Lupus Erythematosus, Systemic; Male; Mice; New Zealand; Ovalbumin; Polysaccharides; Proteins; Species Specificity

Topics: Animals; Antibodies; Antibodies, Antinuclear; Antibody Formation; Autoimmune Diseases; Cattle; DNA; Female; Genes, Dominant; Guinea Pigs; Histocompatibility; Hydralazine; Hypersensitivity, Delayed; Immunity; Immunization; Immunogenetics; Inbreeding; Iodine Isotopes; Male; Methods; Ovalbumin; Serum Albumin, Bovine; Species Specificity

Topics: Animals; Antibodies; Antigens; Autoimmune Diseases; Blood Platelets; Chromium Isotopes; Complement System Proteins; Culture Techniques; Erythrocytes; Haplorhini; Isoantigens; Ovalbumin; Rabbits; Skin

Topics: Animals; Antibody Formation; Antigens; Autoantibodies; Autoimmune Diseases; Cattle; gamma-Globulins; Immune Tolerance; Ovalbumin; Rabbits; Serum Albumin, Bovine; Thyroglobulin; Thyroiditis

Topics: Animals; Antigen-Antibody Reactions; Antigens; Autoimmune Diseases; Muscle Proteins; Myasthenia Gravis; Neuromuscular Junction; Ovalbumin; Rats

Topics: Animals; Antigen-Antibody Reactions; Autoimmune Diseases; Guinea Pigs; Lung Diseases; Lymphocytes; Ovalbumin; Pathology; Research

Topics: Animals; Antibody Formation; Antigen-Antibody Reactions; Autoantibodies; Autoimmune Diseases; Fluorescent Antibody Technique; Freund's Adjuvant; gamma-Globulins; Glomerulonephritis; Humans; Kidney Glomerulus; Lymph Nodes; Lymphocytes; Ovalbumin; Pathology; Plasma Cells; Rabbits; Research; Spleen; Urine

Topics: Animals; Antigens; Autoimmune Diseases; Colitis; Lagomorpha; Ovalbumin; Pathology; Rabbits; Research