sirolimus and Autoimmune-Diseases

Autoimmune Lymphoproliferative Syndrome (ALPS) is an autoimmune disease that has been reported in over 2200 patients. It is a rare, genetic disease where pathogenic variants occur in the extrinsic pathway of apoptosis. Various mutations in different genes, such as FAS, FASL, and CASP10, can result in ALPS. Most commonly, pathogenic variants occur in the FAS receptor. This malfunctioning pathway allows for the abnormal accumulation of lymphocytes, namely CD3 + TCRαβ+CD4 - CD8- (double negative (DN) T) cells, which are a hallmark of the disease. This disease usually presents in childhood with lymphadenopathy and splenomegaly as a result of lymphoproliferation. Over time, these patients may develop cytopenias or lymphomas because of irregularities in the immune system. Current treatments include glucocorticoids, mycophenolate mofetil, sirolimus, immunoglobulin G, and rituximab. These medications serve to manage the symptoms and there are no standardized recommendations for the management of ALPS. The only curative therapy is a bone marrow transplant, but this is rarely done because of the complications. This review serves to broaden the understanding of ALPS by discussing the mechanism of immune dysregulation, how the symptoms manifest, and the mechanisms of treatment. Additionally, we discuss the epidemiology, comorbidities, and medications relating to ALPS patients across the United States using data from Cosmos.

Topics: Autoimmune Diseases; Autoimmune Lymphoproliferative Syndrome; fas Receptor; Humans; Lymphoproliferative Disorders; Mutation; Sirolimus; Splenomegaly

Systemic lupus erythematosus (SLE) is a typical autoimmune disease characterized by multiorgan involvement and marked variability in clinical presentation. SLE pathogenesis includes regulatory T cell dysfunction and antinuclear antibody production. Mammalian target of rapamycin (mTOR), a serine/threonine kinase in the phosphoinositide 3-kinase (PI3K)-related kinase family, is a therapeutic target for autoimmune diseases such as SLE. Rapamycin, an inhibitor of the mTOR signaling pathway, is a macrolide antibiotic with potent immunosuppressive, antiproliferative and antifibrotic effects. Recently, an increasing number of studies have investigated the role of mTOR in regulatory T (Treg) cells and its impact on SLE pathogenesis. This review aims to systematically summarize the role of the mTOR signaling pathway in SLE pathogenesis, Treg cell dysfunction and SLE treatment.

Topics: Autoimmune Diseases; Humans; Lupus Erythematosus, Systemic; Phosphatidylinositol 3-Kinases; Signal Transduction; Sirolimus; T-Lymphocytes, Regulatory; TOR Serine-Threonine Kinases

The cause of autoimmune diseases remains incompletely understood. Here, we highlight recent advances in the role of proinflammatory metabolic pathways in autoimmune disease, including treatment with antioxidants and mechanistic target of rapamycin (mTOR) inhibitors.. Recent studies show that mTOR pathway activation, glucose utilization, mitochondrial oxidative phosphorylation, and antioxidant defenses play critical roles in the pathogenesis of autoimmune diseases, including rheumatoid arthritis, immune thrombocytopenia, Sjögren's syndrome, large vessel vasculitis, and systemic lupus erythematosus. mTOR activity leads to Th1 and Th17 cell proliferation, Treg depletion, plasma cell differentiation, macrophage dysfunction, and increased antibody and immune complex production, ultimately resulting in tissue inflammation. mTOR also affects the function of connective tissue cells, including fibroblast-like synoviocytes, endothelial cells, and podocytes. mTOR inhibition via rapamycin and N-acetylcysteine, and blockade of glucose utilization show clinical efficacy in both mouse models and clinical trials, such as systemic lupus erythematosus.. The mTOR pathway is a central regulator of growth and survival signals, integrating environmental cues to control cell proliferation and differentiation. Activation of mTOR underlies inflammatory lineage specification, and mTOR blockade-based therapies show promising efficacy in several autoimmune diseases.

Topics: Animals; Autoimmune Diseases; Cell Differentiation; Endothelial Cells; Humans; Inflammation; Metabolic Networks and Pathways; Mice; Rheumatic Diseases; Sirolimus; T-Lymphocytes, Regulatory

The growing field of immunometabolism has taught us how metabolic cellular reactions and processes not only provide a means to generate ATP and biosynthetic precursors, but are also a way of controlling immunity and inflammation. Metabolic reprogramming of immune cells is essential for both inflammatory as well as anti-inflammatory responses. Four anti-inflammatory therapies, DMF, Metformin, Methotrexate and Rapamycin all work by affecting metabolism and/or regulating or mimicking endogenous metabolites with anti-inflammatory effects. Evidence is emerging for the targeting of specific metabolic events as a strategy to limit inflammation in different contexts. Here we discuss these recent developments and speculate on the prospect of targeting immunometabolism in the effort to develop novel anti-inflammatory therapeutics. As accumulating evidence for roles of an intricate and elaborate network of metabolic processes, including lipid, amino acid and nucleotide metabolism provides key focal points for developing new therapies, we here turn our attention to glycolysis and the TCA cycle to provide examples of how metabolic intermediates and enzymes can provide potential novel therapeutic targets.

Topics: Anti-Inflammatory Agents; Autoimmune Diseases; Dimethyl Fumarate; Glycolysis; Humans; Immunomodulation; Immunosuppressive Agents; Inflammation; Metformin; Methotrexate; Sirolimus

Autophagy is an essential catabolic program that forms part of the stress response and enables cells to break down their own intracellular components within lysosomes for recycling. Accumulating evidence suggests that autophagy plays vital roles in determining pathological outcomes of immune responses and tumorigenesis. Autophagy regulates innate and adaptive immunity affecting the pathologies of infectious, inflammatory, and autoimmune diseases. In cancer, autophagy appears to play distinct roles depending on the context of the malignancy by either promoting or suppressing key determinants of cancer cell survival. This review covers recent developments in the understanding of autophagy and discusses potential therapeutic interventions that may alter the outcomes of certain diseases.

Topics: Adaptive Immunity; Animals; Autoimmune Diseases; Autophagy; Benzylisoquinolines; Cholecalciferol; Humans; Immune System Diseases; Immunity, Innate; Indoles; Infections; Isoquinolines; Lysosomes; Maprotiline; Metformin; Neoplasms; Phenols; Pyrroles; Resveratrol; Sirolimus; Spermidine; Stilbenes; Tetrahydroisoquinolines; Trehalose

The mechanistic target of rapamycin (mTOR) is a ubiquitous serine/threonine kinase, which plays pivotal roles in integrating growth signals on a cellular level. To support proliferation and survival under stress, two interacting complexes that harbor mTOR, mTORC1 and mTORC2, promote the transcription of genes involved in carbohydrate metabolism and lipogenesis, enhance protein translation, and inhibit autophagy. Although rapamycin was originally developed as an inhibitor of T cell proliferation for preventing organ transplant rejection, its molecular target, mTOR, has been subsequently identified as a central regulator of metabolic cues that drive lineage specification in the immune system. Owing to oxidative stress, the activation of mTORC1 has emerged as a central pathway for the pathogenesis of systemic lupus erythematosus and other autoimmune diseases. Paradoxically, mTORC1 has also been identified as a mediator of the Warburg effect that allows cell survival under hypoxia. Rapamycin and new classes of mTOR inhibitors are being developed to block not only transplant rejection and autoimmunity but also to treat obesity and various forms of cancer. Through preventing these diseases, personalized mTOR blockade holds promise to extend life span.

Topics: Aging; Animals; Autoimmune Diseases; Biomarkers; Humans; Neoplasms; Obesity; Precision Medicine; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Autophagy is a catabolic process that has been shown to have a role in many cellular processes including the removal of excessive or damaged proteins and protein aggregates. The salivary glands play a critical role in oral health, and their secretory capacity may be critically intertwined with the autophagic process. This review describes the role of autophagy activation in normal salivary gland homeostasis and during the glandular stress responses of therapeutic radiation, ductal ligation, autoimmunity, and salivary gland adenoid cystic carcinoma.

Topics: Animals; Autoimmune Diseases; Autophagy; Carcinoma, Adenoid Cystic; Disease Models, Animal; Homeostasis; Humans; Ligation; Salivary Gland Neoplasms; Salivary Glands; Sirolimus; Stress, Physiological

The treatment of auto-immune diseases is evolving and newer agents become available. This review will outline treatment options in children with auto-immune disorders. Treatment with current corticosteroids and azathioprine works in majority but issues of intolerance and incomplete response arise, which led to window of newer immunosuppressants including mycophenolate mofetil, cyclosporine, tacrolimus, sirolimus, and various antibodies of human and animal origin. The newer agents have been studied in fewer numbers of children, so they are not first-line treatment yet but do have a clear role in patients with intolerance or incomplete response to standard therapy.

Topics: Antilymphocyte Serum; Autoimmune Diseases; Azathioprine; Child; Cyclophosphamide; Cyclosporine; Glucocorticoids; Humans; Immunoglobulins, Intravenous; Immunosuppressive Agents; Isoxazoles; Leflunomide; Mercaptopurine; Methotrexate; Mycophenolic Acid; Nitriles; Sirolimus; Tacrolimus

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that functions as a key regulator of cell growth, protein synthesis, and cell-cycle progression through interactions with a number of signalling pathways, including PI3K/AKT, ras, TCL1, and BCR/ABL. Many haematological malignancies have aberrant activation of the mTOR and related signalling pathways. Accordingly, mTOR inhibitors, a class of signal transduction inhibitors that were originally developed as immunosuppressive agents, are being investigated in preclinical models and clinical trials for a number of haematological malignancies. Sirolimus and second-generation mTOR inhibitors, such as temsirolimus and everolimus, are safe and relatively well-tolerated, making them potentially attractive as single agents or in combination with conventional cytotoxics and other targeted therapies. Promising early clinical data suggests activity of mTOR inhibitors in a number of haematological diseases, including acute lymphoblastic leukaemia, chronic myeloid leukaemia, mantle cell lymphoma, anaplastic large cell lymphoma, and lymphoproliferative disorders. This review describes the rationale for using mTOR inhibitors in a variety of haematological diseases with a focus on their use in leukaemia.

Topics: Antineoplastic Agents; Autoimmune Diseases; Hematologic Neoplasms; Humans; Leukemia; Lymphoproliferative Disorders; Protein Kinase Inhibitors; Protein Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

This article examines immunosuppressant transplant agents used to treat the various rheumatic diseases. The older drugs of this type have been used in this dual role for decades. There is a new generation of immunosuppressant drugs with established use in the arena of transplantation medicine. Only recently have the potential rheumatologic applications for these agents been investigated. The authors review in depth the published experience with the newer agents. The authors also discuss novel rheumatologic uses for the older agents that have been described within the past year.

Topics: Autoimmune Diseases; Azathioprine; Clinical Trials as Topic; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Isoxazoles; Leflunomide; Male; Mycophenolic Acid; Rheumatic Diseases; Severity of Illness Index; Sirolimus; Tacrolimus; Transplants; Treatment Outcome

Among all the new immunosuppressive molecules being investigated either preclinically or clinically, four stand out: tacrolimus (FK506), sirolimus (rapamycin), mycophenolate mofetil and leflunomide (and its malononitriloamide analogs). Each drug has distinct mechanisms of immunosuppressive action, and in the past year significant advances have been made in our understanding of the actions of these drugs at the molecular and even atomic levels. Data from recent clinical trials demonstrate that these drugs very effectively suppress graft rejection or autoimmune diseases, validating the pivotal role played by each of their distinct molecular targets in the normal functioning of immune cells.

Topics: Animals; Autoimmune Diseases; Graft Rejection; Humans; Immunosuppressive Agents; Isoxazoles; Leflunomide; Mycophenolic Acid; Polyenes; Pyrimidine Nucleotides; Sirolimus; Tacrolimus; Xenobiotics

Topics: Animals; Autoimmune Diseases; Disease Models, Animal; Immunosuppressive Agents; Neoplasms, Experimental; Organ Transplantation; Polyenes; Sirolimus

Topics: Animals; Autoimmune Diseases; Calcineurin; Calmodulin-Binding Proteins; Carrier Proteins; Cyclosporine; Graft Rejection; Humans; Lymphocyte Activation; Molecular Conformation; Phosphoprotein Phosphatases; Polyenes; Sirolimus; T-Lymphocytes; Tacrolimus; Tacrolimus Binding Proteins

Topics: Animals; Autoimmune Diseases; Humans; Immunosuppressive Agents; Polyenes; Sirolimus

To investigate the safety, tolerability and efficacy of subconjunctival sirolimus injections as a treatment for active, autoimmune, non-necrotizing anterior scleritis.. Phase I/II, single-center, open-label, nonrandomized, prospective pilot study.. Five participants with active, autoimmune, non-necrotizing anterior scleritis with scleral inflammatory grade of ≥1+ in at least 1 quadrant with a history of flares were enrolled. A baseline injection was given, with the primary outcome measure of at least a 2-step reduction or reduction to grade zero in the study eye by 8 weeks. Secondary outcomes included changes in visual acuity and intraocular pressure, ability to taper concomitant immunosuppressive regimen, and number of participants who experienced a disease flare requiring reinjection. Safety outcomes included the number and severity of systemic and ocular toxicities, and vision loss ≥15 ETDRS letters. The study included 6 visits over 4 months with an extension phase to 1 year for participants who met the primary outcome.. All participants (N = 5, 100%; 95% CI [0.60, 1.00]) met the primary outcome in the study eye by the week 8 visit. There was no significant change in mean visual acuity or intraocular pressure. Three out of 5 patients (60%) experienced flares requiring reinjection. No systemic toxicities were observed. Two participants (40%) experienced a localized sterile inflammatory reaction at the site of the injection, which resolved without complication.. Subconjunctival sirolimus leads to a short-term reduction in scleral inflammation, though relapses requiring reinjection do occur. There were no serious adverse events, though a local sterile conjunctival inflammatory reaction was observed.

Topics: Adult; Aged; Anterior Eye Segment; Autoimmune Diseases; Conjunctiva; Female; Humans; Immunosuppressive Agents; Injections, Intraocular; Intraocular Pressure; Male; Middle Aged; Pilot Projects; Prospective Studies; Scleritis; Sirolimus; Visual Acuity

Topics: Apoptosis; Autoimmune Diseases; Autoimmune Lymphoproliferative Syndrome; Child; fas Receptor; Humans; Lymphoproliferative Disorders; Sirolimus

Topics: Autoimmune Diseases; Humans; Immunologic Deficiency Syndromes; Immunosuppressive Agents; Osteochondrodysplasias; Sirolimus

Autoimmune lymphoproliferative syndrome (ALPS) is a rare genetic disorder of lymphocyte homeostasis, resulting from mutations in the Fas apoptotic pathway. It is characterized by non-infectious and non-malignant chronic lymphoproliferation and an increased risk of lymphoid malignancy. The diagnosis of this condition usually combines chronic lymphadenopathy and/or splenomegaly exceeding 6 months, autoimmune cytopenias, with an elevated level of CD3+CD4-CD8- Tαβ lymphocytes, known as "double-negative" T cells. Differential diagnosis includes infections, autoimmune diseases or malignancies. Although clinical examination and laboratory tests are highly suggestive, this disease goes widely unrecognized. We here report, for the first time, the case of ALPS, a Moroccan patient, and aged 8 years, with recurrent fever, splenomegaly and adenopathies. Paraclinical examinations revealed chronic pancytopenia, higher than normal TαÎ

Topics: Autoimmune Diseases; Autoimmune Lymphoproliferative Syndrome; Humans; Immunosuppressive Agents; Pancytopenia; Sirolimus; Splenomegaly

Chronic prostatitis or chronic pelvic pain syndrome (CP/CPPS) is a disease with an unclear pathogenesis. Recent studies have reported that regulatory T (Treg) cells might be involved in the development of CP/CPPS. In this study we aimed to examine the functional role of Treg cells and explore the possible regulatory mechanism of Treg cells in CP/CPPS.. An experimental autoimmune prostatitis (EAP) mouse model was constructed; the numbers and functions of Treg cells in the EAP and control groups were tested. Then, cell differentiation experiments were conducted to evaluate the regulatory effect of autophagy on Treg cell differentiation. Furthermore, autologous CD4. We found that the number and function of Treg cells in the EAP group were diminished compared to those in the control group. Meanwhile, the tolerance of pain in EAP mice had also decreased. Moreover, after using the autophagy activator rapamycin, the expression of the inflammatory cytokines interleukin-1β was decreased and the pain symptoms were alleviated. A mechanistic study found that autophagy activation promoted the differentiation of Treg and increased the suppressive functions of Treg cells, along with the elevated expression of GATA-3 and cytotoxic T lymphocyte antigen 4 (CTLA-4). Furthermore, in vivo administration of the autophagy activator rapamycin had similar effects on recovering the frequency and function of Treg cells as well as the expression of GATA-3 and CTLA-4.. The impaired frequency and function of Treg cells may contribute to the progression of CP/CPPS, and autophagy is a protective mechanism that promotes the differentiation of Treg cells and restores the suppressive functions of Treg cells. Autophagy may be a novel therapeutic option for patients with CP/CPPS.

Topics: Animals; Autoimmune Diseases; Autophagy; Chronic Disease; CTLA-4 Antigen; Disease Models, Animal; GATA3 Transcription Factor; Male; Mice; Mice, Inbred NOD; Pain Measurement; Prostatitis; Rats; Rats, Sprague-Dawley; Sirolimus; T-Lymphocytes, Regulatory; Up-Regulation

Topics: Animals; Autoimmune Diseases; Chorioallantoic Membrane; Conjunctiva; Disease Models, Animal; Drug Compounding; Electroretinography; Erythrocytes; Eye Diseases; Immunosuppressive Agents; Intravitreal Injections; Liposomes; Male; Mice; Micronucleus Tests; Rabbits; Retina; Safety; Sirolimus

Cytoskeletal regulatory protein dysfunction has been etiologically linked to inherited diseases associated with immunodeficiency and autoimmunity, but the mechanisms involved are incompletely understood. Here, we show that conditional

Topics: Animals; Autoimmune Diseases; Autoimmunity; Cell Differentiation; Homeostasis; Immunologic Deficiency Syndromes; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Proto-Oncogene Proteins c-akt; Rapamycin-Insensitive Companion of mTOR Protein; Receptors, Antigen, T-Cell; Regulatory-Associated Protein of mTOR; Signal Transduction; Sirolimus; T-Lymphocytes; TOR Serine-Threonine Kinases; Transcriptome; Wiskott-Aldrich Syndrome Protein Family

Antibody production by the B cell compartment is a crucial part of the adaptive immune response. Dysregulated antibody production in the form of autoantibodies can cause autoimmune disease. To date, B-cell depletion with anti-CD20 antibodies is commonly applied in autoimmunity, but pre-existing plasma cells are not eliminated in this way. Alternative ways of more selective inhibition of antibody production would add to the treatment of these autoimmune diseases. To explore novel therapeutic targets in signaling pathways essential for plasmablast formation and/or immunoglobulin production, we performed a compound screen of almost 200 protein kinase inhibitors in a robust B-cell differentiation culture system. This study yielded 35 small cell-permeable compounds with a reproducible inhibitory effect on B-cell activation and plasmablast formation, among which was the clinically applied mammalian target of rapamycin (mTOR) inhibitor rapamycin. Two additional compounds targeting the phosphoinositide 3-kinase-AKT-mTOR pathway (BKM120 and WYE-354) did not affect proliferation and plasmablast formation, but specifically reduced the immunoglobulin production. With this compound screen we successfully applied a method to investigate therapeutic targets for B-cell differentiation and identified compounds in the phosphoinositide 3-kinase-AKT-mTOR pathway that could specifically inhibit immunoglobulin production only. These drugs may well be explored to be of value in current B-cell-depleting treatment regimens in autoimmune disorders.

Topics: Aminopyridines; Antibody Formation; Autoantibodies; Autoimmune Diseases; B-Lymphocytes; Cell Differentiation; Drug Discovery; High-Throughput Screening Assays; Humans; Lymphocyte Activation; Morpholines; Plasma Cells; Protein Kinase Inhibitors; Purines; Sirolimus; TOR Serine-Threonine Kinases

Topics: Adaptor Proteins, Signal Transducing; Autoimmune Diseases; Disease Management; Disease Susceptibility; Genetic Predisposition to Disease; Humans; Immunosuppressive Agents; Male; Mutation; Pancytopenia; Sirolimus

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

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease (RDD), is a non-neoplastic, lymphoproliferative disorder that usually resolves spontaneously or with minimal conventional chemotherapy. Rarely, SHML can be associated with autoimmune findings. Such cases are often treatment resistant and have high rates of morbidity and mortality. We present a case of a patient with long-standing autoimmunity in the context of SHML, dependent on standard-treatment until he was transitioned to novel monotherapy with sirolimus. Sirolimus treatment resulted in a complete remission, now sustained after discontinuation of all treatments for over 23 months, with no observable long-term sequelae.

Topics: Autoimmune Diseases; Child, Preschool; Histiocytosis, Sinus; Humans; Immunosuppressive Agents; Male; Sirolimus

Patients with autoimmune multilineage cytopenias are often refractory to standard therapies requiring chronic immunosuppression with medications with limited efficacy and high toxicity. We present data on 30 patients treated on a multicenter prospective clinical trial using sirolimus as monotherapy. All children (N = 12) with autoimmune lymphoproliferative syndrome (ALPS) achieved a durable complete response (CR), including rapid improvement in autoimmune disease, lymphadenopathy, and splenomegaly within 1 to 3 months of starting sirolimus. Double-negative T cells were no longer detectable in most, yet other lymphocyte populations were spared, suggesting a targeted effect of sirolimus. We also treated 12 patients with multilineage cytopenias secondary to common variable immunodeficiency (CVID), Evans syndrome (ES), or systemic lupus erythematosus (SLE), and most achieved a CR (N = 8), although the time to CR was often slower than was seen in ALPS. Six children with single-lineage autoimmune cytopenias were treated and only 2 responded. Sirolimus was well tolerated with very few side effects. All of the responding patients have remained on therapy for over 1 year (median, 2 years; range, 1 to 4.5 years). In summary, sirolimus led to CR and durable responses in a majority of children with refractory multilineage autoimmune cytopenias. The responses seen in ALPS patients were profound, suggesting that sirolimus should be considered as a first-line, steroid-sparing treatment of patients needing chronic therapy. The results in other multilineage autoimmune cytopenia cohorts were encouraging, and sirolimus should be considered in children with SLE, ES, and CVID. This trial was registered at www.clinicaltrials.gov as #NCT00392951.

Topics: Adolescent; Adult; Autoimmune Diseases; Child; Child, Preschool; Drug Resistance, Neoplasm; Female; Follow-Up Studies; Hematologic Diseases; Humans; Immunosuppressive Agents; Infant; Male; Neoplasm Recurrence, Local; Neoplasm Staging; Prognosis; Prospective Studies; Salvage Therapy; Sirolimus; Survival Rate; Tissue Distribution; Young Adult

In this issue of Blood, Bride et al report results of the first prospective multi-institutional trial of a long-term single-agent therapy for refractory cytopenias using rapamycin in 30 patients and show remarkable efficacy in children with autoimmune lymphoproliferative syndrome (ALPS).

Topics: Autoimmune Diseases; Drug Resistance, Neoplasm; Female; Hematologic Diseases; Humans; Immunosuppressive Agents; Male; Neoplasm Recurrence, Local; Salvage Therapy; Sirolimus

The therapeutic efficacy of rapamycin conjugated monomethoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) micelles (rapamycin micelles) was evaluated in a rat experimental autoimmune uveitis (EAU) model. Rapamycin micelles exhibited spherical morphology and had a mean particle size of 40nm and a zeta-potential of -0.89mv. The water solubility of rapamycin improved by more than 1000-fold in a micellar formulation. Intravitreal injection of MPEG-PCL micelles did not result in vitreous hemorrhage or retinal detachment. Fluorescence microscopy demonstrated that labeled micelles localized to the retinal pigment epithelium for at least 14 days following injection and the drug concentration of rapamycin micelles in the retinal tissue was significantly higher than unconjugated rapamycin over this period. At the optimal concentration of rapamycin micelles (9μg/eye), clinical signs of EAU were abolished via the downregulation of the Th1 and Th17 response. There were no significant difference in T cell proliferation and delayed-type hypersensitivity between the treatment and control groups, suggesting that the therapeutic effect of rapamycin manifested locally in the eye and not systemically. These results indicate that intravitreal injection of rapamycin micelles is a promising therapy for controlling sterile intraocular inflammation.

Topics: Animals; Autoimmune Diseases; Cell Proliferation; Ciliary Body; Cytokines; Disease Models, Animal; Immunosuppressive Agents; Intravitreal Injections; Micelles; Polyesters; Polyethylene Glycols; Rats, Sprague-Dawley; Retina; Sirolimus; T-Lymphocytes; Uveitis; Vitreous Body

The mammalian target of rapamycin (mTOR) is essential for Th cell proliferation and effector differentiation, making the mTOR signaling network an attractive immunomodulatory target for autoimmune-related diseases. Although direct targeting of mTOR complex-1 (mTORC1) with rapamycin can provide clinical benefit, targeting downstream enzymes has the potential to offer more selective immunosuppression. In this study, we evaluated p70 ribosomal protein S6 Kinase 2 (S6K2), a downstream effector of mTORC1, for its role in T cell function and autoimmunity. S6K2 is a direct substrate of mTORC1, with a potential role in Th17 differentiation suggested by biochemical studies. Using a genetic approach with S6K2 knockout mice, we found that S6K2 loss reduces Th17 skewing and increases regulatory T cell differentiation in vitro when cultured in RPMI 1640 media. However, S6K2 was dispensable for Th17 differentiation in IMDM. In an in vivo experimental autoimmune encephalomyelitis model in which rapamycin suppresses disease, S6K2 knockout mice did not exhibit differences in clinical score or Th17 differentiation. These results suggest that S6K2 is dispensable for Th17-driven autoimmunity and highlight how distinct experimental conditions can produce significantly different results in T cell differentiation.

Topics: Animals; Autoimmune Diseases; Autoimmunity; Cell Differentiation; Cells, Cultured; Immunologic Factors; Immunosuppression Therapy; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Mice, Knockout; Multiprotein Complexes; Ribosomal Protein S6 Kinases, 70-kDa; Sirolimus; Substrate Specificity; T-Lymphocytes, Regulatory; Th17 Cells; TOR Serine-Threonine Kinases

Autoimmune pancreatitis (AIP) in humans invariably responds to steroid treatment, but little is known about the underlying pathogenesis and the benefits of alternative treatments.. To study the pathogenesis, and the efficacy of alternative immunosuppressant agents in the MRL/Mp mouse model of AIP.. MRL/Mp mice were pretreated for 4 weeks with polyinosinic:polycytidylic acid to induce AIP. Pancreatic sections of mice genetically deleted for CTLA-4 were analysed. Blockage of CTLA-4 was achieved by intraperitoneal antibody treatment with 2 μg/g anti-mouse-CD152. Subsequent therapeutic studies were performed for a period of 4 weeks using cyclosporine A (40 μg/g), rapamycin (1 μg/g) or azathioprine (15 μg/g).. Blockage of CTLA-4 in MRL/Mp mice suppressed regulatory T cell (Treg) function and raised the effector T cell (Teff) response with subsequent histomorphological organ destruction, indicating that AIP is a T cell-driven disease. Using an established histopathological score, we found that dexamethasone, cyclosporine A and rapamycin, but less so azathioprine, reduced pancreatic damage. However, the beneficial effects of cyclosporine A and rapamycin were achieved via different mechanisms: cyclosporine A inhibited Teff activation and proliferation whereas rapamycin led to selective expansion of Tregs which subsequently suppressed the Teff response.. The calcineurin inhibitor cyclosporine A and the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, improve the course of AIP in MRL/Mp mice via different mechanisms. These findings further support the concept of autoreactive T cells as key players in the pathogenesis of AIP and suggest that cyclosporine A and rapamycin should be considered for treatment of AIP in humans.

Topics: Animals; Autoimmune Diseases; Azathioprine; Biomarkers; Cell Proliferation; CTLA-4 Antigen; Cyclosporine; Dexamethasone; Drug Administration Schedule; Female; Flow Cytometry; Immunosuppressive Agents; Lymphocyte Activation; Mice; Mice, Inbred Strains; Pancreas; Pancreatitis, Chronic; Poly I-C; Random Allocation; Sirolimus; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Treatment Outcome

Topics: Animals; Autoimmune Diseases; Cyclosporine; Female; Immunosuppressive Agents; Pancreas; Pancreatitis, Chronic; Sirolimus; T-Lymphocyte Subsets

Topics: Animals; Autoimmune Diseases; Cyclosporine; Female; Immunosuppressive Agents; Pancreas; Pancreatitis, Chronic; Sirolimus; T-Lymphocyte Subsets

Previous studies reported that autophagy is activated in human dilated cardiomyopathy (DCM). It is still unknown whether modulating autophagy can improve cardiac function of the failing heart.. We immunized rats with porcine cardiac myosin to set up a model of DCM. Rapamycin, a kind of mTOR inhibitor upregulating autophagy, was given to rats weeks after the immunization at low (1 mg/kg · day i.p.), intermediate (2 mg/kg · day i.p.) and high dose (4 mg/kg · day i.p.) for 2 weeks.. Compared to the control group (ejection fraction, EF = 81.3 ± 3.8%), the average EF decreased in both the DCM group (EF = 56.1 ± 3.3%) and the high-dose rapamycin group (EF = 55.9 ± 3.6%), but recovered in the low-/intermediate-dose rapamycin groups (EF = 64.9 ± 4.6/69.4 ± 4.4%). Phosphorylation of p70s6k and 4E-BP1 decreased and the expression of LC3BI/II increased in all rapamycin groups. Autophagic vacuoles were easily found in these groups. However, body weight was significantly reduced in the rapamycin groups. Furthermore, mortality was increased in the high-dose rapamycin group.. Rapamycin could improve cardiac function of early-stage DCM, but the effect of rapamycin turned out to be biphasic and the effective range appeared narrow.

Topics: Analysis of Variance; Animals; Autoimmune Diseases; Autophagy; Cardiomyopathy, Dilated; Cardiotonic Agents; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Rats; Rats, Inbred Lew; Sirolimus; Stroke Volume; TOR Serine-Threonine Kinases; Weight Loss

Rapamycin, a potent immune modulator, is used to treat transplant rejection and some autoimmune diseases. Uveitis is a potentially severe inflammatory eye disease, and 2 clinical trials of treating uveitis with rapamycin are under way. Unexpectedly, recent research has demonstrated that low dose rapamycin enhances the memory T cell population and function. However, it is unclear how low dose rapamycin influences the immune response in the setting of uveitis.. B10.RIII mice were immunized to induce experimental autoimmune uveitis (EAU). Ocular inflammation of control and rapamycin-treated mice was compared based on histological change. ELISPOT and T cell proliferation assays were performed to assess splenocyte response to ocular antigen. In addition, we examined the effect of rapamycin on activation-induced cell death (AICD) using the MitoCapture assay and Annexin V staining.. Administration of low dose rapamycin exacerbated EAU, whereas treating mice with high dose rapamycin attenuated ocular inflammation. The progression of EAU by low dose rapamycin coincided with the increased frequency of antigen-reactive lymphocytes. Lastly, fewer rapamycin-treated T cells underwent AICD, which might contribute to exaggerated ocular inflammation and the uveitogenic immune response.. These data reveal a paradoxical role for rapamycin in uveitis in a dose-dependent manner. This study has a potentially important clinical implication as rapamycin might cause unwanted consequences dependent on dosing and pharmacokinetics. Thus, more research is needed to further define the mechanism by which low dose rapamycin augments the immune response.

Topics: Animals; Autoimmune Diseases; Cell Count; Disease Progression; Dose-Response Relationship, Drug; Female; Mice; Sirolimus; T-Lymphocytes; Transcription Factors; Uveitis

The efficacy and action mechanism of everolimus in the treatment of experimental autoimmune uveoretinitis (EAU) was analyzed. Disease was induced in B10.RIII mice by immunization with human interphotoreceptor-retinoid-binding protein peptide 161-180 (hIRBPp161-180). Everolimus was administered by oral gavage (5 mg/kg/d) beginning either two days before or 14 days after immunization. Everolimus significantly reduced the histopathological uveitis score compared to sham-treated mice. To examine the effect on the antigen-specific immune response, proliferation ([(3)H]-thymidine test) and delayed-type hypersensitivity (DTH) response were measured. Furthermore, content of T-helper-1, -2, and -17 cytokines were analyzed intraocularly (Bead Array) and in cell culture supernatants from splenocytes (sandwich ELISA). To study the effect on the humoral immune response the presence of antigen-specific serum antibodies was tested (indirect ELISA). The DTH, the humoral immune response, the proliferation of splenocytes and the intraocular Th1, Th2, Th17 cytokine content and in vitro production of Th1 and Th17 cytokines were impaired after everolimus treatment. The study of CD4+CD25+FoxP3+ regulatory T cells (T(reg)) in peripheral blood, draining lymph nodes, and spleen by flow cytometry showed an increased number of splenic T(reg) in mice of the everolimus therapy group. Furthermore the T(reg) of these mice had a higher suppressive capacity than cells from sham-treated mice. These results indicate that the immunosuppressive effect of everolimus on EAU was associated with the suppression of pathogenic effector responses and induction of regulatory T cells.

Topics: Animals; Antibodies; Autoimmune Diseases; Cell Proliferation; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Everolimus; Eye Proteins; Flow Cytometry; Forkhead Transcription Factors; Hypersensitivity, Delayed; Immunosuppressive Agents; Mice; Retinitis; Retinol-Binding Proteins; Sirolimus; Spleen; T-Lymphocytes, Regulatory; Uveitis, Posterior

To explore the effect of rapamycin (RPM) on the expression of B and T lymphocyte attenuate (BTLA) on human peripheral blood T lymphocytes, providing a experimental basis for application of RPM to organ transplantation and autoimmune diseases.. Human peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, and then the T cells were isolated from PBMCs with immunomagnetic beads. Concanavalin A (Con A) used to stimulate and activate the human peripheral blood T cells. The proliferation of T cells was detected by MTT colorimetry. The levels of IL-2 and IFN-γ in cell culture supernatant were detected by ELISA. The expression of BTLA on T cells was assayed by Flow cytometry.. The expression of BTLA on T cells treated with various concentrations (10-1 000 ng/L) of RPM had no significant difference, while had significant difference (P<0.01) by compared with RPM non-treatment group. ELISA detection manifested that compared with the untreated group different concentrations of RPM could significantly inhibit the IL-2 and IFN-γ secretion and significantly inhibited T lymphocyte proliferation (P<0.01).. RPM has little effect on expression BTLA, but has stronger inhibition on lymphocyte proliferation and inflammatory cytokines secretion. Suggesting that RPM is suitable for the treated of organ transplant rejection and autoimmune diseases.

Topics: Autoimmune Diseases; Cell Proliferation; Gene Expression Regulation; Graft Rejection; Humans; Receptors, Immunologic; Sirolimus; T-Lymphocytes

Autoimmune lymphoproliferative syndrome (ALPS) is a genetic disorder of the immune system caused by inadequate induction of apoptosis via the Fas pathway, mainly characterized by generalized lymphadenopathy, splenomegaly, and autoimmune cytopenias, as well as increased risk of lymphoma. Although the clinical course of ALPS is highly variable, without treatment long-term prognosis is unsatisfactory for most patients. ALPS has been treated with most of the existing immunosuppressive agents, with variable success. We hereby present a case of a child with ALPS whose greatly enlarged lymph nodes rapidly regressed upon initiation of rapamycin, a novel potential therapeutic agent in the treatment of ALPS.

Topics: Autoimmune Diseases; Female; Humans; Immunosuppressive Agents; Infant; Lymph Nodes; Lymphatic Diseases; Lymphoproliferative Disorders; Remission Induction; Sirolimus

The development of autoimmune blood cell cytopenias is a potentially life-threatening complication of solid organ transplantation, resulting from T-cell dysregulation from immunosuppressive medications. Conventional treatment with corticosteroids and IVIgG is often unsuccessful as these therapies are unlikely to overcome the T-cell dysregulation. We describe two patients who developed severe autoimmune cytopenias after solid organ transplantation. They had limited response to conventional medications, but had complete resolution of autoimmunity upon transition of immunosuppression from tacrolimus to sirolimus. Altering the immunosuppressive regimen to modify T-cell dysregulation may be beneficial for patients who develop post-transplant autoimmune disease and allow continued preservation of allograft.

Topics: Adolescent; Autoimmune Diseases; Heart Transplantation; Humans; Immunosuppressive Agents; Liver Transplantation; Male; Organ Transplantation; Pancytopenia; Sirolimus; Tacrolimus

Sirolimus and everolimus belong to the novel class of immunosuppressant agents known as proliferation signal inhibitors (PSIs). They act by preventing antigen-driven T cell proliferation. While PSIs are widely used in transplantation, there are few reports of PSI usage in the treatment of autoimmune rheumatic diseases. The author has presented a series in the APLAR 2006 conference. This report summarizes the clinical experience with PSIs in the treatment of resistant or relapsed rheumatic diseases where conventional immunosuppressive agents have failed. This is a retrospective review of patients with various autoimmune rheumatic diseases who had sirolimus and everolimus treatment from the rheumatological clinics of Changi Hospital or the Arthritis and Rheumatism Specialist Medical Centre. The period of review was from April 2006 to April 2008. A total of 46 patients were reviewed, 39 females and 7 males. The racial distribution was 33 Chinese, 7 Malays, and 6 Indians. Their disease conditions were as follows: 26 (57%) rheumatoid arthritis, 7 psoriatic arthritis, 4 systemic lupus erythematosus, 3 scleroderma, 2 anti-Jo-1 syndrome, 2 spondyloarthropathy, 1 MCTD, and 1 vasculitis. All patients had failed at least three DMARDs or immunosuppressants. Twenty-eight patients received sirolimus and 28 patients received everolimus. Overall positive response rate was 48.2%. Twenty-seven percent had adverse events. 20% had no response. 7% relapsed after initial response. PSIs, namely sirolimus and everolimus, are a novel class of immunosuppressants that can be added to the armamentarium of rheumatologists for the treatment of patients with refractory autoimmune rheumatic diseases.

Topics: Adult; Aged; Arthritis, Psoriatic; Arthritis, Rheumatoid; Autoimmune Diseases; Drug Resistance; Everolimus; Female; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Male; Middle Aged; Molecular Structure; Retrospective Studies; Rheumatic Diseases; Scleroderma, Systemic; Sirolimus; Spondylarthropathies; Treatment Outcome; Vasculitis

We report a 74-year-old man with severe chronic primary neutropenia (neutrophil count: 390 per millimeter cube) uncovered following surgery for perianal abscess collection. Clinical, laboratory and roentgenographic findings revealed no abnormality. Antineutrophil antibodies were positive in two consecutive serum samples. Under cyclosporine, neutrophil count reached 1970 per millimeter cube. However, this therapy was discontinued due to new onset of severe renal failure. After six weeks, neutrophil count was 950 per millimeter cube and sirolimus was started, resulting in renal function improvement and resolution of neutropenia.

Topics: Aged; Autoimmune Diseases; Chronic Disease; Diagnosis, Differential; Humans; Immunosuppressive Agents; Leukocyte Count; Male; Neutropenia; Neutrophils; Sirolimus

Previous studies have demonstrated that the NZM2410/NZW 'z' allele of Sle1 on telomeric murine chromosome 1 led to lymphoproliferative autoimmunity, when acting in concert with the FAS(lpr) defect on the C57BL/6 background. The present report shows that the Sle1b sub-locus, harboring the NZM2410/NZW 'z' allele of SLAM, in epistasis with FAS(lpr), may be sufficient to induce lymphoproliferative autoimmunity. Disease in this simplified genetic model is accompanied by significant activation of the AKT signaling axis in both B- and T cells, as evidenced by increased phosphorylation of AKT, mTOR, 4EBP-1 and p70S6K, resulting from increased PI3K and reduced PTEN activity. In addition, blocking this axis using RAD001, an mTOR inhibitor, ameliorated lymphoproliferation and modulated serum IgG anti-nuclear auto-antibodies. Finally, mTOR inhibition also dampened signaling via parallel axes, including the MAPK and NFkB pathways. Hence, hypersignaling via the PI3K/AKT/mTOR axis appears to be an important mechanism underlying autoimmune lymphoproliferative disease, presenting itself as a potential target for therapeutic intervention.

Topics: Animals; Apoptosis; Autoantibodies; Autoimmune Diseases; Epistasis, Genetic; Everolimus; Extracellular Signal-Regulated MAP Kinases; fas Receptor; Female; Immunosuppressive Agents; Lymphocytes; Lymphoproliferative Disorders; Male; Mice; Mice, Congenic; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Multigene Family; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Spleen; Survival Analysis

B and T lymphocyte attenuator (BTLA), a recently identified immune inhibitory receptor, has been demonstrated to have the ability to maintain self-tolerance and transplant-tolerance in mice. However, little is known about the effects of immunosuppressive drugs on the expression of BTLA. In the present study, we observed that the immunosuppressive drug cyclosporin A (CsA) could significantly reduce BTLA but not CD25 and CD69 expression on CD4+ T cells during activation in vitro, while rapamycin (RPM) had little effect on it. Exogenous interleukin-2 (IL-2) failed to reverse the inhibitory effect that CsA had on BTLA expression. Furthermore, phorbol 12-myristate 13-acetate (PMA) or ionomycin alone could efficiently induce BTLA protein expression on CD4+ and CD8+ T cells, while CsA significantly suppressed BTLA expression in this system. The present data indicate that the regulation of BTLA expression on CD4+ T cells does not depend on IL-2 and T cell activation but depends on calcineurin-dependent and calcineurin-independent pathways. The observation that CsA significantly inhibits BTLA expression on CD4+ T cells during activation, suggests that CsA might block the immune tolerance induced by BTLA and potentially increase the susceptibility to autoimmune diseases and graft rejection.

Topics: Animals; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Autoimmune Diseases; Carcinogens; CD4-Positive T-Lymphocytes; Cells, Cultured; Cyclosporine; Female; Gene Expression Regulation; Graft Rejection; Immunosuppressive Agents; Interleukin-2; Interleukin-2 Receptor alpha Subunit; Lectins, C-Type; Lymphocyte Activation; Mice; Receptors, Immunologic; Self Tolerance; Sirolimus; Tetradecanoylphorbol Acetate; Transplantation Tolerance

Sirolimus is a new immunosuppressive drug used to avoid allograft rejection. The immunosuppressive effect of sirolimus is due to inhibition of the mammalian target of rapamycin, necessary for the proliferation and clonal expansion of activated T-cells. Because T-cells play a central role in the pathogenesis of autoimmune disease developed in (NZBxNZW)F1 mice, we evaluated the therapeutic use of sirolimus in such mice. (NZBxNZW)F1 female mice received 1mg/kg/day of sirolimus from 12 to 37 weeks of age. The development of autoimmune disease was evaluated by measuring the serum levels of auto-antibodies (autoAbs) and their immunoglobulin isotypes, prevalence of glomerulonephritis and mortality rates. Sirolimus directly inhibited production of autoAbs, glomerular deposits of immunoglobulins and development of proteinuria; also the survival of these mice was prolonged. Our results demonstrate the beneficial effects of sirolimus in preventing the development of lupus disease in (NZBxNZW)F1 female mice.

Topics: Animals; Autoantibodies; Autoimmune Diseases; Female; Immunoglobulin Isotypes; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice; Mice, Inbred NZB; Proteinuria; Sirolimus; Survival Rate; Treatment Outcome

Mechanisms underlying lymphocyte infiltration of the thyroid gland and orbit in Graves' disease (GD) are poorly understood. The IGF-I receptor (IGF-IR) is a newly recognized self-antigen that, when activated in GD fibroblasts by IGF-I or GD-IgGs, provokes the expression of IL-16 and RANTES (regulated upon activation, normal T cell expressed and secreted)-dependent T lymphocyte chemoattraction and hyaluronan synthesis. IL-16 is a CD4(+)-specific ligand, and RANTES is a C-C chemokine. Here we report that IGF-I and GD-IgG could induce IL-16 and RANTES in cultured human thyrocytes in a time-dependent manner. Importantly, human TSH failed to induce either chemoattractant. This induction could be attenuated by dexamethasone. Rapamycin, a specific inhibitor of the FRAP/mammalian target of rapamycin/p70(s6k) pathway, prevented GD-IgG-provoked IL-16 synthesis. IH7, a monoclonal antibody directed at IGF-IR also blocked the induction of chemoattraction as well as RANTES mRNA synthesis. Our findings suggest that thyrocytes can be activated by GD-IgG and IGF-I to express powerful T-cell chemoattractants. These actions of GD-IgG appear to be mediated through pathways independent of the TSH receptor. Thus, in GD, thyrocytes may participate directly in lymphocyte recruitment through their expression of IL-16 and RANTES.

Topics: Antibodies, Monoclonal; Autoimmune Diseases; Cell Movement; Cells, Cultured; Chemokine CCL5; Dexamethasone; Graves Disease; Humans; Immunoglobulin G; Interleukin-16; Receptor, IGF Type 1; Receptors, Thyrotropin; RNA, Messenger; Sirolimus; T-Lymphocytes; Thyroid Gland

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of abnormal lymphocyte survival caused by defective Fas-mediated apoptosis, leading to lymphadenopathy, hepatosplenomegaly, and an increased number of double-negative T cells (DNTs). Treatment options for patients with ALPS are limited. Rapamycin has been shown to induce apoptosis in normal and malignant lymphocytes. Since ALPS is caused by defective lymphocyte apoptosis, we hypothesized that rapamycin would be effective in treating ALPS. We tested this hypothesis using rapamycin in murine models of ALPS. We followed treatment response with serial assessment of DNTs by flow cytometry in blood and lymphoid tissue, by serial monitoring of lymph node and spleen size with ultrasonography, and by enzyme-linked immunosorbent assay (ELISA) for anti-double-stranded DNA (dsDNA) antibodies. Three-dimensional ultrasound measurements in the mice correlated to actual tissue measurements at death (r = .9648). We found a dramatic and statistically significant decrease in DNTs, lymphadenopathy, splenomegaly, and autoantibodies after only 4 weeks when comparing rapamycin-treated mice with controls. Rapamycin induced apoptosis through the intrinsic mitochondrial pathway. We compared rapamycin to mycophenolate mofetil, a second-line agent used to treat ALPS, and found rapamycin's control of lymphoproliferation was superior. We conclude that rapamycin is an effective treatment for murine ALPS and should be explored as treatment for affected humans.

Topics: Animals; Antibodies, Antinuclear; Autoimmune Diseases; Immunosuppressive Agents; Lymphoid Tissue; Lymphoproliferative Disorders; Mice; Mice, Inbred CBA; Mice, Mutant Strains; Mycophenolic Acid; Protein Kinases; Signal Transduction; Sirolimus; T-Lymphocyte Subsets; TOR Serine-Threonine Kinases

Dermatomyositis is an autoimmune condition that results in significant morbidity and mortality through effects on muscle and skin. Corticosteroids are the mainstay of therapy of dermatomyositis, and severe morbidity and mortality occurs in part through the known long-term side effects of chronic steroid use. In addition, dermatomyositis is commonly associated with underlying malignancy, and high-dose steroids may adversely impair treatment of these malignancies. We describe the first use of rapamycin in a young patient with dermatomyositis.

Topics: Adult; Autoimmune Diseases; Dermatomyositis; Female; Glucocorticoids; Humans; Hypertriglyceridemia; Immunosuppressive Agents; Prednisone; Sirolimus

Sirolimus is an immunosuppressant that inhibits interleukin (IL)-2 signaling of T-cell proliferation but not IL-2-induced T-cell apoptosis. Therefore, we hypothesized that administration of IL-2, together with sirolimus, might shift T-cell proliferation to apoptosis and prevent autoimmune destruction of islet beta-cells. We found that sirolimus and IL-2 therapy of female NOD mice, beginning at age 10 weeks, was synergistic in preventing diabetes development, and disease prevention continued for 13 weeks after stopping sirolimus and IL-2 therapy. Similarly, sirolimus and IL-2 were synergistic in protecting syngeneic islet grafts from recurrent autoimmune destruction after transplantation in diabetic NOD mice, and diabetes did not recur after stopping sirolimus and IL-2 combination therapy. Immunocytochemical examination of islet grafts revealed significantly decreased numbers of leukocytes together with increased apoptosis of these cells in mice treated with sirolimus and IL-2, whereas beta-cells were more numerous, and significantly fewer were apoptotic. In addition, Th1-type cells (gamma-interferon-positive and IL-2(+)) were decreased the most, and Th2-type cells (IL-4(+) and IL-10(+)) and Th3-type cells (transforming growth factor-beta1(+)) were increased the most in islet grafts of sirolimus and IL-2-treated mice. We conclude that 1) combination therapy with sirolimus and IL-2 is synergistic in protecting islet beta-cells from autoimmune destruction; 2) diabetes prevention continues after withdrawal of therapy; and 3) the mechanism of protection involves a shift from Th1- to Th2- and Th3-type cytokine-producing cells, possibly due to deletion of autoreactive Th1 cells.

Topics: Animals; Apoptosis; Autoimmune Diseases; Diabetes Mellitus, Type 1; Drug Synergism; Drug Therapy, Combination; Female; Immunohistochemistry; Immunosuppressive Agents; Interferon-gamma; Interleukin-2; Islets of Langerhans; Islets of Langerhans Transplantation; Mice; Mice, Inbred NOD; Sirolimus; Tumor Necrosis Factor-alpha

Cyclosporine (CsA) and FK506 are structurally unrelated immunosuppressants, but function in similar ways. FK506 and rapamycin (RAPA), on the other hand, have structural similarities, but act by different mechanisms to yield immunosuppression. Besides their immunosuppressive action, CsA and FK506 are known to interfere with T-cell development. CsA treatment after lethal X-irradiation and syngeneic bone marrow transplantation results in autoimmune disease, which is referred to as CsA-induced autoimmunity. In this study, we examined the effect of RAPA on T-cell development by flow cytometry and immunohistochemistry in female Lewis and Brown Norway rats. Irradiation and syngeneic bone marrow transplantation were performed before a 4-week course of RAPA administration to determine de novo T-cell development in relation to possible autoimmune phenomena. RAPA interfered with the maturation of thymocytes to the CD4+CD8+ DP stage, which resulted in a relative increase in TCRalphabeta(-) immature thymocytes, localized in a rim along the outer cortex. The thymus of RAPA-treated animals had a thinner cortex, leading to stronger thymic atrophy. In the periphery, only a few T cells were observed at the end of RAPA treatment. In the Lewis rat, a normal CD4/CD8 T-cell ratio and an increased Th1/Th2 ratio was observed within the T-cell population. Six weeks after cessation of RAPA therapy, the T-cell compartment was restored to normal, with respect to number and phenotype. In Brown Norway rats, however, T-cell areas were barely detectable at the end of RAPA treatment. The CD4/CD8 T-cell ratio was decreased as a result of a lower number of CD4 T cells; the Th1/Th2 ratio was increased but Th2 remained higher. Similar to Lewis rats, the situation was almost normalized 6 weeks after cessation of RAPA administration. However, Brown Norway rats, in contrast to Lewis rats, showed T-cell infiltration and concomitant induction of MHC class II in the submandibular salivary gland, as well as insulitis, in the pancreas. Possible relationships to Sjogren's disease and diabetes remain to be established.

Topics: Animals; Autoimmune Diseases; Autoimmunity; Disease Susceptibility; Female; Flow Cytometry; Immunosuppressive Agents; Phenotype; Polyenes; Rats; Rats, Inbred BN; Rats, Inbred Lew; Sirolimus; T-Lymphocyte Subsets; T-Lymphocytes; Th1 Cells; Th2 Cells; Thymus Gland

Immunosuppressive drugs currently available for the treatment of autoimmune diseases display a narrow therapeutic window between efficacy and toxic side effects. The use of combinations of drugs that have a synergistic effect may expand this window and reduce the risk of toxicity. We evaluated the combination effect of rapamycin (Rapa) and cyclosporin A (CsA) in an autoimmune disease model of the eye. The dose-effect relationship of Rapa with CsA was measured in vitro on the inhibition of proliferation of retinal S-Ag-primed lymphocytes. A median effect analysis was performed and a combination index (CI) calculated for 50% inhibition of proliferation. Rapa and CsA were markedly synergistic over a wide dose range (lowest CI = 0.31). Calculated dose reduction factors indicated that Rapa could be reduced nine-fold and CsA reduced five-fold when these drugs were used in combination. These reduced doses were tested in vivo for the treatment of experimental autoimmune uveoretinitis (EAU). Twelve of 15 rats treated with CsA, 2 mg/kg/day, developed EAU with a median severity of 2.5. Fourteen of 15 rats treated with Rapa, 0.01 mg/kg/day, developed EAU with a median severity of 3.25. Complete inhibition of EAU was achieved in all 15 animals treated with the combination of Rapa and CsA (combined vs CsA alone, p < 0.0002; combined vs Rapa alone, p < 0.00001). The demonstrated synergistic relationship between Rapa and CsA will allow the use of reduced doses of each drug to achieve a therapeutic effect. The use of lower doses may reduce the toxicity of these drugs for the treatment of autoimmune uveitis.

Topics: Animals; Antigens; Arrestin; Autoimmune Diseases; Cyclosporine; Drug Synergism; Eye Proteins; Immunosuppressive Agents; Lymph Nodes; Lymphocyte Activation; Male; Polyenes; Rats; Rats, Inbred Lew; Retinitis; Sirolimus; Uveitis

Topics: Animals; Autoimmune Diseases; Cyclosporine; Drug Evaluation, Preclinical; Female; Glomerulonephritis; Immunosuppressive Agents; Mercuric Chloride; Polyenes; Proteinuria; Rats; Rats, Inbred BN; Sirolimus; Splenomegaly; Weight Loss

We investigated the ability of the macrolide antifungal agent rapamycin (RAPA) to inhibit murine graft-vs-host disease induced across the MHC barrier. An optimum dose (1.5 mg/kg) given for 14 days beginning on the day of transplant (and then three times weekly until 1 mo) effectively and significantly (p < 0.001) protected 80% of irradiated B10.BR recipients of C57Bl/6 bone marrow/spleen grafts for over 90 days, whereas 80% of control mice died by day 37. Using a congenic model in which a mixture of Ly5.1+ bone marrow (T cell-depleted) and Ly5.2+ spleen cells allowed us to distinguish mature and immature cells, we found that RAPA inhibits the splenic expansion of mature donor-derived T cells in B10.BR recipients after bone marrow transplantation. In addition, phenotyping studies revealed that RAPA causes a massive reduction of immature CD4+CD8+ T cells in the thymus, indicating that RAPA probably interferes with maturation of immature CD3-CD4-CD8- T cells to CD4+CD8+ T cells. There was also a predilection toward development or intrathymic retention of the more mature CD3+CD4-CD8+ or CD3+CD4+CD8- cells in the thymus of long term survivors. These same observations were made in different experiments with mice given syngeneic bone marrow transplantation and RAPA. However, RAPA administration was associated with the occurrence of an autoimmune-like syndrome, consisting of ulcerative dermatitis, hepatic bile duct proliferation, and nondestructive lymphoid peribronchiolar infiltration of the lung. RAPA interfered with the deletion of potentially self-reactive T cells that occurs in thymic development. The failure of clonal deletion was observed in allogeneic and syngeneic transplants given RAPA, although only the allografted mice experienced an autoimmune-like syndrome. Some, but not all, of the nondeleted V beta populations were functionally active. These new findings bear certain dissimilarities to the syndrome and lesions observed with cyclosporin A treatment, particularly in the observation of bile duct proliferation and ulcerative skin lesions. Nonetheless, because of the potent effect of RAPA in preventing lethal graft-vs-host induced across the MHC, further investigation of the immune consequences of this highly effective compound is warranted.

Topics: Animals; Autoimmune Diseases; Bone Marrow Transplantation; CD4 Antigens; CD8 Antigens; Clonal Deletion; Cyclosporine; Graft vs Host Disease; Immunosuppressive Agents; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Polyenes; Receptors, Antigen, T-Cell, alpha-beta; Sirolimus; T-Lymphocyte Subsets; Transplantation, Homologous

Topics: Administration, Oral; Animals; Arthritis; Arthritis, Experimental; Autoimmune Diseases; Blood Glucose; Diabetes Mellitus, Type 1; Drinking; Encephalomyelitis, Autoimmune, Experimental; Female; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Male; Mice; Mice, Inbred DBA; Mice, Inbred NOD; Polyenes; Rats; Rats, Inbred Lew; Sirolimus

We have examined the effects of FK-506 and of the struturally related macrolide rapamycin, which bind with high affinity to a specific binding protein (FKBP), to evaluate the involvement of this protein in the release of preformed (histamine) and de novo synthesized inflammatory mediators (sulfidopeptide leukotriene C4 and prostaglandin D2) from mast cells isolated from human lung parenchyma. FK-506 (0.1 to 300 nM) concentration dependently inhibited histamine release from lung parenchymal mast cells activated by anti-IgE. FK-506 was more potent in lung mast cells than in basophils (IC50 = 1.13 +/- 0.46 nM vs 5.28 +/- 0.88 nM; p less than 0.001), whereas the maximal inhibitory effect was higher in basophils than in lung mast cells (88.4 +/- 2.5% vs 76.4 +/- 3.8%; p less than 0.01). FK-506 had little or no inhibitory effect on histamine release from lung mast cells challenged with compound A23187, whereas it completely suppressed A23187-induced histamine release from basophils. FK-506 also inhibited the de novo synthesis of 5-lipoxygenase (sulfidopeptide leukotriene C4) and cyclo-oxygenase (prostaglandin D2) metabolites of arachidonic acid from mast cells challenged with anti-IgE. Unlike in basophils, Il-3 (3 to 30 ng/ml) did not modify anti-IgE- or A23187-induced histamine release from lung mast cells nor did it reverse the inhibitory effect of FK-506. Rapamycin (3 to 300 nM) had little or no effect on the release of histamine from lung mast cells, but it was a competitive antagonist of the inhibitory effect of FK-506 on anti-IgE-induced histamine release from human mast cells with a dissociation constant of about 12 nM. These data indicate that FK-506 is a potent anti-inflammatory agent that acts on human lung mast cells presumably by binding to a receptor site (i.e., FKBP).

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Autoimmune Diseases; Calcimycin; Cells, Cultured; Histamine Release; Humans; Immunoglobulin E; Interleukin-3; Leukotrienes; Mast Cells; Polyenes; Sirolimus; Tacrolimus