ovalbumin and Graft-vs-Host-Disease

A major emphasis of our studies has been on developing a better understanding of how and why the skin serves as a target for immune reactions as well as how the skin evades becoming a target for destruction. For these studies we developed transgenic mice that express a membrane-tethered form of a model self antigen, chicken ovalbumin (mOVA), under the control of a keratin 14 (K14) promoter. K14-mOVA transgenic mice that express OVA mRNA and protein in the epithelia have been assessed for their immune responsiveness to OVA and are being used as targets for T cells obtained from OT-1 transgenic mice whose CD8+ T cells carry a Vα2/Vβ5-transgenic T cell receptor with specificity for the OVA(257-264)-peptides (OVAp) in association with class I MHC antigens. Some of the K14-mOVA transgenic mice develop a graft-versus-host-like disease (GvHD) when the OT-1 cells are injected while others appear to be tolerant to the OT-1 cells. We found that γc cytokines, especially IL-15, determine whether autoimmunity or tolerance ensues in K14-mOVA Tg mice. We also developed transgenic mice that express soluble OVA under the control of a K14 promoter (K14-sOVA) that die within 5-8 days after adoptive transfer of OT-1 cells and identified these mice as a model for more acute GvHD-like reactions. Spontaneous autoimmunity occurs when these K14-sOVA mice are crossed with the OT-I mice. In contrast, we found that preventive or therapeutic OVAp injections induced a dose-dependent increase in survival. In this review the characterization of 5 strains of K14-OVATg mice and underlying mechanisms involved in autoimmune reactions in these Tg mice are discussed. We also describe a strategy to break tolerance and describe how the autoimmunity can be obviated using OVAp. Finally, a historical overview of using transgenic mice to assess the mechanisms of tolerance is also provided.

Topics: Animals; Autoantigens; Autoimmunity; CD8-Positive T-Lymphocytes; Disease Models, Animal; Graft vs Host Disease; Humans; Immune Tolerance; Keratin-14; Mice; Mice, Transgenic; Ovalbumin; Promoter Regions, Genetic; Receptors, Antigen, T-Cell; Skin

Topics: Animals; Graft vs Host Disease; Helminthiasis; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Immunoglobulin G; In Vitro Techniques; Interleukin-4; Ovalbumin

Topics: Animals; Dermatitis, Contact; Dogs; Drug Eruptions; Graft vs Host Disease; Graft vs Host Reaction; Guinea Pigs; Haptens; Hypersensitivity, Delayed; Kidney Transplantation; Leukocytes; Lymphocytes; Lymphoid Tissue; Macrophages; Microscopy, Electron; Microscopy, Phase-Contrast; Ovalbumin; Plasma Cells; Rabbits; Skin; Skin Transplantation; Transplantation Immunology; Transplantation, Homologous; Tuberculin Test

Topics: Animals; Apoptosis; CD8-Positive T-Lymphocytes; Dermatitis; Graft vs Host Disease; Keratinocytes; Mice; Mice, Inbred C57BL; Ovalbumin; Protein Precursors

T-cell receptor (TCR)-transgenic models of acute graft-versus-host disease (aGvHD) offer a straightforward and highly controlled approach to study the mechanisms and consequences of T-cell activation following allogeneic hematopoietic stem cell transplantation (aHSCT). Here, we report that aHSCT involving OT-I mice as donors, carrying an ovalbumin-specific CD8+ TCR, and Act-mOVA mice as recipients, expressing membrane-bound ovalbumin driven by the β-actin promoter, induces lethal aGvHD in a CD8+ T-cell-dependent, highly reproducible manner, within 4-7 days. Tracking of UBC-GFP/OT-I graft CD8+ T cells disclosed heavy infiltration of the gastrointestinal tract, liver, and lungs at the onset of the disease, and histology confirmed hallmark features of gastrointestinal aGVHD, hepatic aGvHD, and aGvHD-associated lymphocytic bronchitis in infiltrated organs. However, T-cell infiltration was virtually absent in the skin, a key target organ of human aGvHD, and histology confirmed the absence of cutaneous aGVHD, as well. We show that the model allows studying CD8+ T-cell responses in situ, as selective recovery of graft CD45.1/OT-I CD8+ T cells from target organs is simple and feasible by automated tissue dissociation and subsequent cell sorting. Assessment of interferon-gamma production by flow cytometry, granzyme-B release by ELISA, TREC assay, and whole-genome gene expression profiling confirmed that isolated graft CD8+ T cells remained intact, underwent clonal expansion, and exerted effector functions in all affected tissues. Taken together, these data demonstrate that the OT-I/Act-mOVA model is suitable to study the CD8+ T-cell-mediated effector mechanisms in a disease closely resembling fatal human gastrointestinal and hepatic aGVHD that may develop after aHSCT using HLA-matched unrelated donors.

Topics: Actins; Acute Disease; Animals; CD8-Positive T-Lymphocytes; Cell Membrane; Cell Proliferation; Cell Tracking; Chickens; Clone Cells; Disease Models, Animal; Flow Cytometry; Gene Expression Profiling; Graft vs Host Disease; Mice, Inbred C57BL; Mice, Transgenic; Organ Specificity; Ovalbumin; Reproducibility of Results; T-Lymphocytes, Cytotoxic

Co-transplantation of hematopoietic stem cells with those engineered to express leukemia-reactive T-cell receptors (TCRs) and differentiated ex vivo into precursor T cells (preTs) may reduce the risk of leukemia relapse. As expression of potentially self-(leukemia-) reactive TCRs will lead to negative selection or provoke autoimmunity upon thymic maturation, we investigated a novel concept whereby TCR expression set under the control of an inducible promoter would allow timely controlled TCR expression. After in vivo maturation and gene induction, preTs developed potent anti-leukemia effects. Engineered preTs provided protection even after repeated leukemia challenges by giving rise to effector and central memory cells. Importantly, adoptive transfer of TCR-transduced allogeneic preTs mediated anti-leukemia effect without evoking graft-versus-host disease (GVHD). Earlier transgene induction forced CD8(+) T-cell development was required to obtain a mature T-cell subset of targeted specificity, allowed engineered T cells to efficiently pass positive selection and abrogated the endogenous T-cell repertoire. Later induction favored CD4 differentiation and failed to produce a leukemia-reactive population emphasizing the dominant role of positive selection. Taken together, we provide new functional insights for the employment of TCR-engineered precursor cells as a controllable immunotherapeutic modality with significant anti-leukemia activity.

Topics: Adoptive Transfer; Animals; Flow Cytometry; Genetic Engineering; Graft vs Host Disease; Graft vs Leukemia Effect; Hematopoietic Stem Cell Transplantation; Humans; Leukemia, Myeloid; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Precursor Cells, T-Lymphoid; Promoter Regions, Genetic; Receptors, Antigen, T-Cell; Transplantation, Homologous

During acute graft-versus-host disease (aGVHD) in mice, autoreactive T cells can be generated de novo in the host thymus implying an impairment in self-tolerance induction. As a possible mechanism, we have previously reported that mature medullary thymic epithelial cells (mTEC(high)) expressing the autoimmune regulator are targets of donor T-cell alloimmunity during aGVHD. A decline in mTEC(high) cell pool size, which purges individual tissue-restricted peripheral self-antigens (TRA) from the total thymic ectopic TRA repertoire, weakens the platform for central tolerance induction. Here we provide evidence in a transgenic mouse system using ovalbumin (OVA) as a model surrogate TRA that the de novo production of OVA-specific CD4(+) T cells during acute GVHD is a direct consequence of impaired thymic ectopic OVA expression in mTEC(high) cells. Our data, therefore, indicate that a functional compromise of the medullary mTEC(high) compartment may link alloimmunity to the development of autoimmunity during chronic GVHD.

Topics: Animals; Autoantigens; Autoimmunity; CD4-Positive T-Lymphocytes; Female; Graft vs Host Disease; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Self Tolerance; Thymus Gland

The pathomechanisms underlying the development of cutaneous graft-versus-host disease (GVHD) are incompletely defined. We previously reported that K14-mOVA mice expressing membrane ovalbumin (mOVA), driven by the keratin 14 (K14) promoter, developed GVHD-like mucocutaneous disease and weight loss following transfer of OVA-specific, CD8(+) OT-I T cells. In this study, we demonstrate that early in the course of disease, the kinetics of epidermal expression of C-X-C motif chemokine ligand 9 (CXCL9) and CXCL10, interferon-γ-inducible chemokines that bind the C-X-C motif chemokine receptor 3 (CXCR3) receptor, coincides with CXCR3 expression by OT-I cells in secondary lymphoid organs. Recruitment of OT-I cells into the skin began by day 5 with progressive accumulation through day 13 post transfer. Transfer of CXCR3-knockout (CXCR3KO) OT-I cells into K14-mOVA mice resulted in strikingly attenuated skin disease. CXCR3KO OT-I cells retained full activation and effector function, but preferentially accumulated in the spleen, in contrast to wild-type (WT) OT-I cells that accumulated in skin-draining lymph nodes. Moreover, OT-I cells accounted for a significantly reduced percentage of skin-infiltrating lymphocytes in mice receiving CXCR3KO OT-I cells compared with WT OT-I cells. These results identify CXCR3 as being critical to the skin-selective effector T-cell recruitment underlying autoreactive GVHD, suggesting CXCR3 as a potential target in the treatment of GVHD and related skin diseases.

Topics: Animals; CD3 Complex; CD8-Positive T-Lymphocytes; Cell Movement; Cell Separation; Chemokine CXCL10; Chemokine CXCL9; Epidermis; Flow Cytometry; Graft vs Host Disease; Keratin-14; Ligands; Lymph Nodes; Lymphocytes; Mice; Mice, Knockout; Ovalbumin; Promoter Regions, Genetic; Receptors, CXCR3; Skin; T-Lymphocytes; Up-Regulation

Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) are threatened by potentially lethal viral manifestations like cytomegalovirus (CMV) reactivation. Because the success of today's virostatic treatment is limited by side effects and resistance development, adoptive transfer of virus-specific memory T cells derived from the stem cell donor has been proposed as an alternative therapeutic strategy. In this context, dose minimization of adoptively transferred T cells might be warranted for the avoidance of graft-versus-host disease (GVHD), in particular in prophylactic settings after T-cell-depleting allo-HSCT protocols. To establish a lower limit for successful adoptive T-cell therapy, we conducted low-dose CD8(+) T-cell transfers in the well-established murine Listeria monocytogenes (L.m.) infection model. Major histocompatibility complex-Streptamer-enriched antigen-specific CD62L(hi) but not CD62L(lo) CD8(+) memory T cells proliferated, differentiated, and protected against L.m. infections after prophylactic application. Even progenies derived from a single CD62L(hi) L.m.-specific CD8(+) T cell could be protective against bacterial challenge. In analogy, low-dose transfers of Streptamer-enriched human CMV-specific CD8(+) T cells into allo-HSCT recipients led to strong pathogen-specific T-cell expansion in a compassionate-use setting. In summary, low-dose adoptive T-cell transfer (ACT) could be a promising strategy, particularly for prophylactic treatment of infectious complications after allo-HSCT.

Topics: Adolescent; Animals; CD8-Positive T-Lymphocytes; Cell Differentiation; Cell Proliferation; Child; Cytomegalovirus; Cytomegalovirus Infections; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Homeodomain Proteins; Humans; Immunization; Immunotherapy, Adoptive; Male; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Severe Combined Immunodeficiency; Transplantation, Homologous; Virus Activation

We have developed K14-mOVA transgenic (Tg) mice that express membrane-associated ovalbumin (mOVA) under the control of a K14 promoter, as well as double Tg mice, by crossing them with OT-I mice that have a TCR recognizing the OVA peptide. When injected with CD8(+) OT-I cells, K14-mOVA Tg mice develop graft-versus-host disease (GVHD), whereas double Tg mice are protected. This suggests that, in double Tg mice, regulatory mechanisms may prevent infused OT-I cells from inducing GVHD. We demonstrated that, after adoptive transfer, TCRαβ(+)CD3(+)CD4(-)CD8(-)NK1.1(-) double-negative (DN) T cells are increased in the peripheral lymphoid organs and skin of double Tg mice and exhibit a Vα2(+)Vβ5(+)TCR that has the same TCR specificity as OT-I cells. These DN T cells isolated from tolerant double Tg mice proliferated in response to OVA peptide and produced IFN-γ in the presence of IL-2. These cells could also suppress the proliferation of OT-I cells and were able to specifically kill activated OT-I cells through Fas/Fas ligand interaction. These findings suggest that DN T cells that accumulate in double Tg mice have regulatory functions and may have a role in the maintenance of peripheral tolerance in vivo.

Topics: Adoptive Transfer; Animals; CD3 Complex; CD4 Antigens; CD8 Antigens; CD8-Positive T-Lymphocytes; Cell Division; Cells, Cultured; Disease Models, Animal; Female; Graft vs Host Disease; Immune Tolerance; Interferon-gamma; Interleukin-2; Male; Mice; Mice, Transgenic; Ovalbumin; Skin Diseases; T-Lymphocytes, Regulatory

Topics: Adipocytes; Alginates; Animals; Glucuronic Acid; Graft vs Host Disease; Hexuronic Acids; Immunomodulation; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Osteoblasts; Ovalbumin; Survival Rate; T-Lymphocytes

The precise contribution(s) of skin dendritic cells (DCs) to immune responses in the skin has not been well delineated. We developed an intradermal (i.d.) injection model in which CD8+ T (OT-I) cells that express ovalbumin (OVA) peptide-specific TCRs (Valpha2/Vbeta5) are delivered directly to the dermis of transgenic (Tg) mice expressing OVA in the epidermis. After i.d. injection, these mice reliably develop skin graft-versus-host disease (GVHD) by day 7. To determine the relative contribution of Langerhans cells (LCs) to the ensuing GVHD-like reaction, we generated K14-OVA x Langerin-diphtheria-toxin-receptor (Langerin-DTR) Tg mice to allow conditional ablation of LCs in the epidermis. To delineate the role of dermal DCs (dDCs) in the reaction, we also generated K14-OVA Tg chimeras using beta(2)-microglobulin-deficient (beta(2)m) congenic donor bone marrow cells. Dermal DCs in these mice cannot present OVA to autoreactive T cells (OT-I cells), whereas the LCs are antigen presentation-competent. Unexpectedly, OT-I cell injection into diphtheria toxin (DT)-treated beta(2)m --> K14-OVA x Langerin-DTR Tg mice resulted in skin GVHD. Thus, in vivo, both LC and dDC appear to be dispensable for the induction of keratinocyte-directed, CD8-mediated effector immune responses. Furthermore and surprisingly, OVA-expressing epidermal cells depleted of LCs that could not initiate allogeneic epidermal lymphocyte reactions activated naive OT-I cells in vitro. These results indicate that keratinocytes may function as accessory cells competent to prime naive skin-reactive T cells.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://network.nature.com/group/jidclub.

Topics: Adoptive Transfer; Animals; Antigen Presentation; Antigen-Presenting Cells; CD8-Positive T-Lymphocytes; Cell Communication; Cell Line; Dermis; Diphtheria Toxin; Epidermal Cells; Epidermis; Genes, MHC Class II; Graft vs Host Disease; Keratinocytes; Langerhans Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin

When used as therapy for hematopoietic malignancies, allogeneic BM transplantation (BMT) relies on the graft-versus-leukemia (GVL) effect to eradicate residual tumor cells through immunologic mechanisms. However, graft-versus-host disease (GVHD), which is initiated by alloreactive donor T cells that recognize mismatched major and/or minor histocompatibility antigens and cause severe damage to hematopoietic and epithelial tissues, is a potentially lethal complication of allogeneic BMT. To enhance the therapeutic potential of BMT, we sought to find therapeutic targets that could inhibit GVHD while preserving GVL and immune responses to infectious agents. We show here that T cell responses triggered in mice by either Listeria monocytogenes or administration of antigen and adjuvant were relatively well preserved in the absence of PKC isoform theta (PKCtheta), a key regulator of TCR signaling. In contrast, PKCtheta was required for alloreactivity and GVHD induction. Furthermore, absence of PKCtheta raised the threshold for T cell activation, which selectively affected alloresponses. Most importantly, PKCtheta-deficient T cells retained the ability to respond to virus infection and to induce GVL effect after BMT. These findings suggest PKCtheta is a potentially unique therapeutic target required for GVHD induction but not for GVL or protective responses to infectious agents.

Topics: Animals; Bone Marrow Transplantation; Female; Graft vs Host Disease; Graft vs Leukemia Effect; In Vitro Techniques; Isoantigens; Isoenzymes; Leukemia, Experimental; Listeria monocytogenes; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, Transgenic; Ovalbumin; Peptide Fragments; Protein Kinase C; Protein Kinase C-theta; Retroviridae Infections; Signal Transduction; T-Lymphocytes

To elucidate the mechanisms controlling peripheral tolerance, we established two transgenic (Tg) mouse strains expressing different levels of membrane-bound OVA (mOVA) as a skin-associated self-Ag. When we transferred autoreactive TCR-Tg CD8 T cells (OT-I cells), keratin 14 (K14)-mOVA(high) Tg mice developed autoreactive skin disease (graft-vs-host disease (GVHD)-like skin lesions) while K14-mOVA(low) Tg mice did not. OT-I cells in K14-mOVA(high) Tg mice were fully activated with full development of effector function. In contrast, OT-I cells in K14-mOVA(low) Tg mice proliferated but did not gain effector function. Exogenous IL-15 altered the functional status of OT-I cells and concomitantly induced disease in K14-mOVA(low) Tg mice. Conversely, neutralization of endogenous IL-15 activity in K14-mOVA(high) Tg mice attenuated GVHD-like skin lesions induced by OT-I cell transfer. Futhermore, K14-mOVA(high) Tg mice on IL-15 knockout or IL-15Ralpha knockout backgrounds did not develop skin lesions after adoptive transfer of OT-I cells. These results identify IL-15 as an indispensable costimulator that can determine the functional fate of autoreactive CD8 T cells and whether immunity or tolerance ensues, and they suggest that inhibition of IL-15 function may be efficacious in blocking expression of autoimmunity where a breach in peripheral tolerance is suspected.

Topics: Animals; Autoimmunity; CD8-Positive T-Lymphocytes; Disease Models, Animal; Graft vs Host Disease; Interleukin-15; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin

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

4-(2',4'- Difluorobiphenyl-4-yl)-2-methylbutyric acid (deoxoflobufen, VUFB 19053, CAS 847475-35-8) has been developed as a new omega-biphenyl-alkanoic acid and studied in comparison with the racemic form of 4-(2',4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoic acid (flobufen, CAS 112344-52-2). The compounds were tested in a series of models including acute inflammation induced by carrageenan, adjuvant arthritis, in vitro inhibition of the leuktotriene B4 (LTB4) production, reaction of the graft versus the host (GVHR), production of specific antibodies against ovalbumin, peritoneal exudate formation induced by thioglycollate and phagocytosis of thioglycollate-stimulated mouse peritoneal macrophages. Deoxoflobufen exhibited strong anti-inflammatory, antiarthritic and immunomodulatory effects in most of the performed tests. Anti-inflammatory and antiarthritic effects are fully comparable with those of flobufen, however, the compound is less toxic and has apparently stronger immunomodulating effects.

Topics: Animals; Anti-Inflammatory Agents; Antibody Formation; Area Under Curve; Arthritis, Experimental; Biphenyl Compounds; Butyrates; Carrageenan; Cell Adhesion; Exudates and Transudates; Female; Graft vs Host Disease; Hypersensitivity, Delayed; Inflammation; Leukotriene B4; Macrophages; Mice; Ovalbumin; Peritonitis; Phagocytosis; Pleurisy; Rats; Structure-Activity Relationship; Thioglycolates

To understand the mechanisms involved in immunological tolerance to skin-associated antigens, we have developed transgenic (Tg) mice that express a model self-antigen, membrane-bound chicken ovalbumin (OVA), under the control of a keratin 14 (K14) promoter. K14-mOVA Tg mice express OVA mRNA in the epidermis, and appear normal. K14-mOVA Tg mice failed to mount T cell and delayed type hypersensitivity reactions to OVA, suggesting that the Tg mice were tolerant to OVA. Skin dendritic cells, including Langerhans cells, may contribute to the tolerance induction because migratory skin DC derived from K14-mOVA efficiently activated CD8(+) T cells from OVA-specific T-cell receptor (Va2/Vb5) Tg (OT-I) mice. OT-I cells expanded and accumulated in skin-draining lymph nodes after intravenous injected into K14-mOVA mice and exhibited activation markers. Graft-versus-host disease-like skin lesions appeared in K14-mOVA mice by day 7 after injection of OT-I cells. These studies demonstrate that K14-mOVA Tg mice are susceptible to an autoimmunelike skin disease induced by passively transferred naïve CD8(+) OVA T-cell receptor Tg T cells, and serve as a good model for understanding self-tolerance and for the investigation of the pathogenesis, treatment and potential prevention of cell-mediated autoimmune reactions in skin.

Topics: Adoptive Transfer; Animals; Autoantigens; CD8-Positive T-Lymphocytes; Cell Movement; Gene Expression; Graft vs Host Disease; Hypersensitivity, Delayed; Keratin-14; Keratins; Mice; Mice, Transgenic; Ovalbumin; Promoter Regions, Genetic; Skin Diseases; Transgenes

A novel IFN-like molecule, limitin, was recently identified and revealed to suppress B lymphopoiesis through the IFN-alphabeta receptor, although it lacked growth suppression on myeloid and erythroid progenitors. Here we have studied diverse effects of limitin on T lymphocytes and compared limitin with previously known IFNs. Like IFN-alpha and -beta, limitin modified immunity in the following responses. It suppressed mitogen- and Ag-induced T cell proliferation through inhibiting the responsiveness to exogenous IL-2 rather than suppressing the production of IL-2. In contrast, limitin enhanced cytotoxic T lymphocyte activity associated with the perforin-granzyme pathway. To evaluate the effect of limitin in vivo, a lethal graft-versus-host disease assay was established. Limitin-treatment of host mice resulted in the enhancement of graft-versus-host disease. Limitin did not influence thymocyte development either in fetal thymus organ cultures or in newborn mice injected with limitin-Ig, suggesting that limitin is distinguishable from IFN-alpha and -beta. From these findings, it can be speculated that the human homolog of limitin may be applicable for clinical usage because of its IFN-like activities with low adverse effects on, for example, T lymphopoiesis, erythropoiesis, and myelopoiesis.

Topics: Adjuvants, Immunologic; Animals; Cell Division; Cytokines; Cytotoxicity, Immunologic; Drug Evaluation, Preclinical; Graft vs Host Disease; Hematopoiesis; Immunosuppressive Agents; Interferon-alpha; Interferon-beta; Interleukin-2; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Muromonab-CD3; Organ Culture Techniques; Ovalbumin; Radiation Chimera; T-Lymphocyte Subsets; Thymus Gland

Induction and maintenance of Ag-specific tolerance are pivotal for immune homeostasis, prevention of autoimmune disorders, and the goal of transplantation. Recent studies suggest that certain cytokines, notably IL-10 and TGF-beta, may play a role in down-regulating immune functions. To further examine the role of cytokines in Ag-specific hyporesponsiveness, murine CD4+ T cells were exposed ex vivo to alloantigen-bearing stimulators in the presence of exogenous IL-10 and/or TGF-beta. Primary but not secondary alloantigen proliferative responses were inhibited by IL-10 alone. However, the combined addition of IL-10 + TGF-beta markedly induced alloantigen hyporesponsiveness in both primary and secondary MLR cultures. Alloantigen-specific hyporesponsiveness was observed also under conditions in which nominal Ag responses were intact. In adoptive transfer experiments, IL-10 + TGF-beta-treated CD4+ T cells, but not T cells treated with either cytokine alone, were markedly impaired in inducing graft-vs-host disease alloresponses to MHC class II disparate recipients. These data provide the first formal evidence that IL-10 and TGF-beta have at least an additive effect in inducing alloantigen-specific tolerance, and that in vitro cytokines can be exploited to suppress CD4+ T cell-mediated Ag-specific responses in vivo.

Topics: Amino Acid Sequence; Animals; Antigens; CD4-Positive T-Lymphocytes; Cells, Cultured; Drug Combinations; Epitopes, T-Lymphocyte; Graft vs Host Disease; Immune Tolerance; Immunosuppressive Agents; Interleukin-10; Isoantigens; Lymphocyte Culture Test, Mixed; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Molecular Sequence Data; Ovalbumin; Transforming Growth Factor beta

Animal studies have shown that antigens present within the gut play an important role in the development of acute graft versus host disease (GvHD) following allogeneic bone marrow transplantation (BMT). In previous studies, inert sugars have been found to penetrate the small bowel mucosa after conditioning therapy for BMT; endotoxaemia can also occur during acute GvHD. Data on absorption of antigenic proteins across the gut following BMT in humans have not been presented as yet.. Six patients undergoing allogeneic BMT were studied to determine whether enteric ovalbumin absorption increased or endotoxaemia developed during acute GvHD.. Three patients had minimal antigenaemia and no detectable endotoxaemia before receiving conditioning therapy. At the onset of acute GvHD, however, much higher ovalbumin concentrations were detected in those patients with severe antigenaemia. Serum concentrations of specific antiovalbumin IgG and IgA, or antiendotoxin IgM or IgG had no bearing on detectable IgG or IgM ovalbumin or endotoxin concentrations. In five of six patients, small bowel permeability increased, as tested by the lactulose/mannitol sugar absorption test, but detectable ovalbumin absorption increased in only three of these and only two developed endotoxaemia.. Antigens present within the gut can cross the mucosal epithelium during acute GvHD, probably resulting in an enhanced immune response.

Topics: Acute Disease; Antigens; Bone Marrow Transplantation; Endotoxins; Graft vs Host Disease; Humans; Immunoglobulin A; Immunoglobulin G; Ovalbumin; Transplantation, Homologous

Graft-versus-host disease across minor histocompatibility barriers was induced in two different models by transplanting allogeneic bone marrow and spleen cells into irradiated H-2-compatible recipient mice. In this report, we show that administration of peptides with high binding affinity for the respective class II major histocompatibility complex molecules after transplantation is capable of preventing the development of graft-versus-host disease in two different murine models. The peptides used were myelin basic protein residues 1 through 11 with alanine at position 4 (Ac 1-11[4A]) for I-Au (A alpha uA beta u), and the antigenic core sequence 323 through 339 of ovalbumin with lysine and methionine extension (KM core) for I-As (A alpha sA beta s). In both systems, the mechanism of prevention was found to be major histocompatibility complex-associated, because nonbinding control peptides did not have any effect. Engraftment of allogeneic bone marrow cells was shown by polymerase chain reaction analysis of DNA polymorphisms in a microsatellite region within the murine interleukin-5 gene.

Topics: Amino Acid Sequence; Animals; Base Sequence; Bone Marrow Transplantation; Female; Graft vs Host Disease; H-2 Antigens; Histocompatibility; Histocompatibility Antigens Class II; Interleukin-5; Mice; Molecular Sequence Data; Myelin Basic Protein; Ovalbumin; Peptide Fragments; Polymerase Chain Reaction; Repetitive Sequences, Nucleic Acid; Spleen; T-Lymphocytes

Topics: Acute Disease; Animals; Autoantibodies; Chronic Disease; Erythrocytes; Graft vs Host Disease; Hemagglutination; Hepatitis; Hypersensitivity, Delayed; Immunity, Cellular; Immunoglobulins; Jaundice; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Muscle, Smooth; Ovalbumin; Reoviridae Infections; Sheep; Time Factors

Topics: Animals; Antibodies, Antinuclear; Antigen-Antibody Complex; Electrophoresis; Female; Fluorescent Antibody Technique; Glomerulonephritis; Graft vs Host Disease; Immune Sera; Immunization; Immunoglobulin G; Kidney Glomerulus; Lupus Erythematosus, Systemic; Male; Mice; Microscopy, Electron; Nephritis; Ovalbumin; Rabbits