Therapeutic Approach For Autoimmune Diseases Research Articles

The Future of CAR T Therapeutics to Treat Autoimmune Disorders.

The concept of chimeric antigen receptor (CAR) T cell therapy emerged from cancer immunotherapy and has been rapidly adapted and developed for the treatment of autoimmune, especially B-cell-driven, diseases since the first publication of an article featuring a patient with systemic lupus erythematosus in 2021. Phase II studies are about to start, but up to now, only case reports and small series have been published. In contrast to hemato-oncological diseases, where an aggressive response to malignant cells and long-lasting persistence of CAR T cells has been aimed at and observed in many patients, this is not the case with autoimmune diseases but might not be necessary to control disease. Future studies will focus on the optimal target but also on the optimal level of immunogenicity. The latter can be influenced by numerous modulations that affect not only cytokine release but also regulation. In addition, there are potential applications in regulatory cells such as CAR regulatory T cells (Treg). The question of toxicity reduction must also be addressed, as long-term complications such as the potential development of malignant diseases, infections, or cytopenia must be considered even more critically in the area of autoimmune diseases than is the case for patients with oncologic diseases. Alternative antibody-based therapies using the same target (e.g., CD3/CD19 bispecific targeting antibodies) have not been used in these patients and might also be considered in the future. In conclusion, CAR T cell therapy represents a promising therapeutic approach for autoimmune diseases, offering a targeted strategy to modulate immune responses and restore immune tolerance.

Regulatory T Cell Dysfunction in Autoimmune Diseases.

Regulatory T cells (Tregs), a suppressive subpopulation of T cells, are potent mediators of peripheral tolerance, responsible for immune homeostasis. Many autoimmune diseases exhibit disruptions in Treg function or quantity, resulting in an imbalance between protective and pathogenic immune cells. Selective expansion or manipulation of Tregs is a promising therapeutic approach for autoimmune diseases. However, the extensive diversity of Treg subpopulations and the multiple approaches used for Treg identification leads to high complexity, making it difficult to develop a successful treatment capable of modulating Tregs. In this review, we describe the suppressive mechanisms, subpopulations, classification, and identification methodology for Tregs, and their role in the pathogenesis of autoimmune diseases.

Preclinical Pharmacology Characterization of Sovleplenib (HMPL-523), an Orally Available Syk Inhibitor.

Spleen tyrosine kinase (Syk) is an intracellular tyrosine kinase involved in the signal transduction in immune cells mainly. Its aberrant regulation is associated with diversified allergic disorders, autoimmune diseases and B cell malignancies. Therefore, inhibition of Syk is considered a reasonable approach to treat autoimmune/inflammatory diseases and B cell malignancies. Here we described the preclinical characterization of sovleplenib, a novel, highly potent and selective, oral Syk inhibitor, in several rodent autoimmune disease models. Sovleplenib potently inhibited Syk activity in a recombinant enzymatic assay and Syk-dependent cellular functions in various immune cell lines and human whole blood in vitro. Furthermore, sovleplenib, by oral administration, demonstrated strong in vivo efficacies in murine models of immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and chronic graft-versus-host disease (cGVHD), and a rat model of collagen induced arthritis (CIA) respectively, in a dose-dependent manner. Collectively, these results clearly supported sovleplenib as a therapeutic agent in the treatment of autoimmune diseases. Sovleplenib is being globally developed for ITP (Phase III, NCT05029635, Phase Ib/II, NCT03951623), wAIHA (Phase II/III, NCT05535933) and B-cell lymphoma (Phase I, NCT02857998, NCT03779113). SIGNIFICANCE STATEMENT: Syk is a key mediator of signaling pathways downstream of a wide array of receptors important for immune functions, including the B cell receptor, immunoglobulin receptors bearing Fc receptors. Inhibition of Syk could provide a novel therapeutic approach for autoimmune diseases and hematologic malignancies. The manuscript describes the preclinical pharmacology characterization of sovleplenib, a novel Syk inhibitor, in enzymatic and cellular assays in vitro and several murine autoimmune disease models in vivo.

A target-based discovery from a parasitic helminth as a novel therapeutic approach for autoimmune diseases

Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic helminths have co-evolved with hosts to generate immunological privilege and immune tolerance through inducing Tregs. Thus, constructing a "Tregs-induction"-based discovery pipeline from parasitic helminth is a promising strategy to control autoimmune and inflammatory diseases. The gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC) were used to isolate immunomodulatory components from the egg extracts of Schistosoma japonicum. The extracted peptides were evaluated for their effects on Tregs suppressive functions using flow cytometry, ELISA and T cell suppression assay. Finally, we carried out colitis and psoriasis models to evaluate the function of Tregs induced by helminth-derived peptide invivo. Here, based on target-driven discovery strategy, we successfully identified a small 3kDa peptide (SjDX5-53) from egg extracts of schistosome, which promoted both human and murine Tregs production. SjDX5-53 presented immunosuppressive function by arresting dendritic cells (DCs) at an immature state and augmenting the proportion and suppressive capacity of Tregs. In mouse models, SjDX5-53 protected mice against autoimmune-related colitis and psoriasis through inducing Tregs and inhibiting inflammatory T-helper (Th) 1 and Th17 responses. SjDX5-53 exhibited the promising therapeutic effects in alleviating the phenotype of immune-related colitis and psoriasis. This study displayed a screening and validation pipeline of the inducer of Tregs from helminth eggs, highlighting the discovery of new biologics inspired by co-evolution of hosts and their parasites. This study was supported by the Natural Science Foundation of China (82272368) and Natural Science Foundation of Jiangsu Province (BK20211586).

The intricate relationship between autoimmunity disease and neutrophils death patterns: a love-hate story.

Autoimmune diseases are pathological conditions that result from the misidentification of self-antigens in immune system, leading to host tissue damage and destruction. These diseases can affect different organs and systems, including the blood, joints, skin, and muscles. Despite the significant progress made in comprehending the underlying pathogenesis, the complete mechanism of autoimmune disease is still not entirely understood. In autoimmune diseases, the innate immunocytes are not functioning properly: they are either abnormally activated or physically disabled. As a vital member of innate immunocyte, neutrophils and their modes of death are influenced by the microenvironment of different autoimmune diseases due to their short lifespan and diverse death modes. Related to neutrophil death pathways, apoptosis is the most frequent cell death form of neutrophil non-lytic morphology, delayed or aberrant apoptosis may contribute to the development anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). In addition, NETosis, necroptosis and pyroptosis which are parts of lytic morphology exacerbate disease progression through various mechanisms in autoimmune diseases. This review aims to summarize recent advancements in understanding neutrophil death modes in various autoimmune diseases and provide insights into the development of novel therapeutic approaches for autoimmune diseases.

Evolving concepts of host-pathobiont interactions in autoimmunity.

Autoimmune diseases are complex, multifactorial diseases with a polygenic trait and diverse environmental factors that contribute to triggering and exacerbating each disorder. The human microbiome is increasingly implicated in the multistep pathogenesis of autoimmune diseases. We summarize here the latest developments in the field of how the microbiota interacts with the host on a cellular and molecular level. We review how pathobionts evolve within the gut of autoimmune-prone hosts to translocate to secondary lymphoid tissues. On mucosal sites and in non-gut tissues, pathobionts trigger autoimmune pathways through various mechanisms, including cross-reactivity with autoantigens and secretion of metabolites that alter immune functions. A better understanding of these mechanisms will hasten the development of unconventional therapeutic approaches for autoimmune diseases.

OR24-2 Cutting-edge translational strategies in type 1 diabetes

Abstract Background and purpose of the study The overall goal of this study is to develop precision-targeted therapies for type 1 diabetes (T1D) by blocking the presentation of pancreatic antigens to T cells using an innovative translational approach. There is currently no curative therapy for T1D and the only available treatment is insulin replacement, which – although being life-saving – remains problematic and can be associated with often fatal high or low glucose levels. We hypothesize that the presentation of pathogenic pancreatic peptides to T cells within the HLA-DQ8 pocket is a key trigger in T1D, and that blocking the peptide binding to this pocket can be harnessed to treat/prevent the autoimmune response targeting beta cells in T1D. We propose to block antigen presentation to treat/prevent autoimmunity in T1D using retro-inverso D-amino acid peptides (RIPs). To test our hypothesis, we used the following tools: recombinant human HLA-DQ8, human B cells homozygous for HLA-DQ8, humanized mice expressing human HLA-DQ8, NOD mice, and peripheral blood mononuclear cells (PBMCs) isolated from new onset HLA-DQ8 T1D patients. All of them represent exquisite translational instruments to evaluate in vitro, ex vivo, and in vivo the functional role of our RIPs in preventing beta cell destruction. Summary of results We have identified a RIP (RI-CT) that inhibits InsB: 9-23 binding to recombinant HLA-DQ8 molecule, as well as its binding to HLA-DQ8 expressed on a human B-cell line. Specifically, RI-CT averted T-cell activation in a mixed lymphocyte reaction containing human DQ8 cells loaded with InsB: 9-23 peptide and murine T-cells expressing a human TCR specific for the InsB: 9-23–DQ8 complex. These results were also confirmed in humanized transgenic B6-DQ8 mice (KO for murine MHC-II) both ex vivo and in vivo, as shown by decreased production of pro-inflammatory cytokines (including IL-2 and IFN-γ) and reduced lymphocyte proliferation. Moreover, RI-CT prevents autoimmune diabetes in NOD mice as demonstrated by a significant decrease in pancreatic immune cell infiltration in treated mice versus controls. Importantly, at 25 weeks of age 70% of RI-CT treated mice were protected from the development of diabetes, while as expected 80% of control NOD mice had developed the disease. Interestingly, RI-CT injection also altered T-cell subpopulations in NOD mice significantly decreasing CD8 expression and significantly increasing Foxp3 levels in treated mice. Of note, RI-CT significantly inhibits InsB: 9-23-mediated lymphocyte activation in peripheral blood mononuclear cells isolated from new onset DQ8-T1D patients. Conclusions In summary, we discovered a RIP that blocks InsB: 9-23 binding to HLA-DQ8 and its presentation to T-cells averting beta cells destruction, and that delays T1D in NOD mice. These data set the stage for using our approach of blocking antigen presentation by RIP as a novel therapeutic approach for autoimmune diseases in general. Presentation: Monday, June 13, 2022 11:15 a.m. - 11:30 a.m.

Rheumatoid factor IgM autoantibodies control IgG homeostasis.

Rheumatoid arthritis is an autoimmune disease characterized by joint inflammation due to autoantibodies targeting multiple self-proteins. Most patients with poor prognosis show elevated titers of IgM antibodies specifically binding to IgG. Such autoreactive antibodies are referred to as rheumatoid factor (RF). However, their biological function and contribution to disease progression remains elusive. We have recently shown that autoreactive antibodies are present in healthy individuals and play an important role in regulating physiological processes. This regulatory mechanism is determined by the class and affinity of the autoreactive antibody, as low-affinity autoreactive IgM neutralizes the recognized autoantigen while high-affinity IgM protects its autoantigen from degradation. Here, we show that RFs possessing a high affinity and mono-specificity to IgG have a stabilizing effect on IgG, whereas low-affinity polyreactive RFs neutralize IgG in vivo. These results suggest that autoreactive IgM antibodies recognizing IgG play a crucial role in regulating IgG homeostasis and that a disbalance between IgM-mediated IgG degradation and stabilization might affect the onset and progression of autoimmune diseases. Consequently, restoring this balance using low-affinity anti-IgG IgM might be a promising therapeutic approach for autoimmune diseases involving autoreactive IgG.

Plasma miRNA Profile of Crohn's Disease and Rheumatoid Arthritis Patients.

Simple SummaryMicroRNAs are small, noncoding RNA, around 23 nt long molecules, expressed in different cell types and involved in post-transcriptional regulation. Importantly, these unique molecules can act directly in cells expressing them, but can also be secreted into blood affecting gene expression in distant or adjacent target cells, thus representing valuable circulating biomarkers of different diseases. In addition, miRNA gene target prediction indicates the important role in pathogenesis of a variety of autoimmune diseases, including Crohn’s disease (CD) and rheumatoid arthritis (RA). Our study of blood circulating miRNAs indicated that there are 99 differentially expressed miRNAs in CD patients and 57 in RA patients, when comparing with healthy individuals. This high number of differentially expressed miRNAs in both autoimmune diseases allowed us to select over 400 different biological processes that were similarly regulated between both groups of patients, which can pave the way to future mechanistic studies for better diagnosis or treatment for patients with Crohn’s disease and rheumatoid arthritis.Crohn’s disease (CD) and rheumatoid arthritis (RA) are immune mediated inflammatory diseases. Several studies indicate a role for microRNAs (miRNAs) in the pathogenesis of a variety of autoimmune diseases, including CD and RA. Our study’s goal was to investigate circulating miRNAs in CD and RA patients to identify potential new biomarkers for early detection and personalized therapeutic approaches for autoimmune diseases. For this study, subjects with CD (n = 7), RA (n = 8) and healthy controls (n = 7) were recruited, and plasma was collected for miRNA sequencing. Comparison of the expression patterns of miRNAs between CD and healthy patients identified 99 differentially expressed miRNAs. Out of these miRNAs, 4 were down regulated, while 95 were up regulated. Comparison of miRNAs between RA and healthy patients identified 57 differentially expressed miRNAs. Out of those, 12 were down regulated, while 45 were up regulated. For all the miRNAs down regulated in CD and RA patients, 420 GO terms for biological processes were similarly regulated between both groups. Therefore, the identification of new plasma miRNAs allows the emergence of new biomarkers that can assist in the diagnosis and treatment of CD and RA.

Human Wharton's Jelly-Derived Mesenchymal Stromal Cells Primed by Tumor Necrosis Factor-α and Interferon-γ Modulate the Innate and Adaptive Immune Cells of Type 1 Diabetic Patients.

The unique immunomodulation and immunosuppressive potential of Wharton’s jelly-derived mesenchymal stromal cells (WJ-MSCs) make them a promising therapeutic approach for autoimmune diseases including type 1 diabetes (T1D). The immunomodulatory effect of MSCs is exerted either by cell-cell contact or by secretome secretion. Cell-cell contact is a critical mechanism by which MSCs regulate immune-responses and generate immune regulatory cells such as tolerogenic dendritic cells (tolDCs) and regulatory T cell (Tregs). In this study, we primed WJ-MSCs with TNF-α and IFN-γ and investigated the immunomodulatory properties of primed WJ-MSCs on mature dendritic cells (mDCs) and activated T cells differentiated from mononuclear cells (MNCs) of T1D patient’s. Our findings revealed that primed WJ-MSCs impaired the antigen-mediated immunity, upregulated immune-tolerance genes and downregulated immune-response genes. We also found an increase in the production of anti-inflammatory cytokines and suppression of the production of pro-inflammatory cytokines. Significant upregulation of FOXP3, IL10 and TGFB1 augmented an immunosuppressive effect on adaptive T cell immunity which represented a strong evidence in support of the formation of Tregs. Furthermore, upregulation of many critical genes involved in the immune-tolerance mechanism (IDO1 and PTGES2/PTGS) was detected. Interestingly, upregulation of ENTPD1/NT5E genes express a strong evidence to switch immunostimulatory response toward immunoregulatory response. We conclude that WJ-MSCs primed by TNF-α and IFN-γ may represent a promising tool to treat the autoimmune disorders and can provide a new evidence to consider MSCs- based therapeutic approach for the treatment of TID.

Rescue of autoimmune hepatitis by soluble MHC class II molecules in an altered concanavalin A-induced experimental model.

BackgroundSoluble major histocompatibility complex class II (sMHCII) molecules have been described to maintain tolerance through the suppression of autoreactive T lymphocytes. In order to evaluate their ability to rescue autoimmune hepatitis (AIH) symptoms, the present work attempted to administer sMHCII molecules to an in vitro as well as in vivo concanavalin A (ConA)‐induced AIH model.MethodsThe in vitro AIH model consisted of splenocyte stimulation with ConA in the presence or absence of serum‐isolated sMHCII molecules. An in vivo ConA‐modified model with or without sMHCII treatment was developed. The cytokine profile in culture supernatants and serum was tested by ELISA. Cell markers were evaluated by immunofluorescence, while cell proliferation by tritiated thymidine uptake. AIH symptoms were assessed by daily observations for the establishment of a disease severity scoring system and liver histology was evaluated using a biomolecular imager.ResultsThe presence of sMHCII molecules in the ConA‐stimulated cell cultures leads to a significant reduction of cell proliferation. The administration of sMHCII molecules to the ConA‐treated animals showed a significant reduction in the levels of IL‐2, IL‐4, and IL‐10, as well as a decrease in the number of spleen CD4+ and CD8+ cells. Upon development of a scoring system, it was shown that the sMHCII treatment was accompanied by a slower progression of the disease, while rescuing fibrotic liver morphology.ConclusionThe results presented in this study confirm the ability of sMHCII proteins to alleviate autoimmune hepatitis, possibly highlighting new therapeutic approaches for autoimmune diseases.

Novel mRNA-based Therapeutics to Modulate T and B Cell Signaling and Function

Abstract Autoimmunity is considered a T cell driven disease and in many cases B cells contribute to the underlying pathology. Many of the current therapeutics used to treat autoimmunity and organ transplantation are broadly immunosuppressive and can result in increased susceptibility to infection and cancer. We have designed several mRNA-encoded chimeric polypeptides containing an inhibitory motif and a location motif that are expected to disrupt signaling downstream of the T and B cell receptor (T/BCR) and blunt activation. We found that lipid nanoparticle (LNP)-encapsulated mRNA encoding TCR disruptors (Immune LNP-TCRi) containing either a constitutively active CSK (CA.Csk), ITIM, or SHIP1 inhibitory motif reduced in vitro proliferation and cytokine production in primary T cells. In an in vivo xeno-GVHD model Immune LNP-TCRi significantly delayed T cell-mediated mortality. BCR disruptors were engineered by creating mRNA encoding chimeric proteins containing components of the BCR complex (CD79a, CD79b and CD19) and either the CD22 intracellular ITIM or SHIP1 inhibitory motif. Encapsulated in Immune LNP, these BCR disruptors downregulated B cell activation as measured by phosphorylation of Syk, suppressed BCR-induced IgM/G, IL6 and IL10 secretion, as well as reduced B cell in vitro proliferation. In NSG mice engrafted with healthy human PBMC, Immune LNP-BCRi also suppressed humoral immunity against tetanus toxoid and reduced serum IgM and IgG levels. Unlike corticosteroids and anti-CD20 Ab, co-engagement of chimeric T/BCR disruptors did not significant decrease the number of lymphocytes. Thus, amplification of T/BCR disruptor pathway may represent a novel therapeutic approach for autoimmune diseases.

Understanding Fc Receptor Involvement in Inflammatory Diseases: From Mechanisms to New Therapeutic Tools.

Fc receptors (FcRs) belong to the ITAM-associated receptor family. FcRs control the humoral and innate immunity which are essential for appropriate responses to infections and prevention of chronic inflammation or auto-immune diseases. Following their crosslinking by immune complexes, FcRs play various roles such as modulation of the immune response by released cytokines or of phagocytosis. Here, we review FcR involvement in pathologies leading notably to altered intracellular signaling with functionally relevant consequences to the host, and targeting of Fc receptors as therapeutic approaches. Special emphasis will be given to some FcRs, such as the FcαRI, the FcγRIIA and the FcγRIIIA, which behave like the ancient god Janus depending on the ITAM motif to inhibit or activate immune responses depending on their targeting by monomeric/dimeric immunoglobulins or by immune complexes. This ITAM duality has been recently defined as inhibitory or activating ITAM (ITAMi or ITAMa) which are controlled by Src family kinases. Involvement of various ITAM-bearing FcRs observed during infectious or autoimmune diseases is associated with allelic variants, changes in ligand binding ability responsible for host defense perturbation. During auto-immune diseases such as rheumatoid arthritis, lupus or immune thrombocytopenia, the autoantibodies and immune complexes lead to inflammation through FcR aggregation. We will discuss the role of FcRs in autoimmune diseases, and focus on novel approaches to target FcRs for resolution of antibody-mediated autoimmunity. We will finally also discuss the down-regulation of FcR functionality as a therapeutic approach for autoimmune diseases.

The importance of microRNAs in the development of systemic autoimmune disorders

MicroRNAs (miRNAs) are 18-25 nucleotide long, single stranded, endogenous, non-coding small RNAs playing an important role in regulating gene expression at posttranscriptional level. miRNAs control approximately 90% of protein-coding genes, and play a central role in various biological processes including immune cell lineage commitment, differentiation, proliferation, apoptosis and maintenance of immune homeostasis. Changes in the expression of certain miRNAs may lead to the development of many diseases, including systemic autoimmune diseases. In this study, we summarize the biogenesis of miRNAs, their role in regulation of the immune system, and review the latest research findings in systemic lupus erythematosus, primary Sjögren's syndrome, rheumatoid arthritis and systemic sclerosis. In the future, miRNAs may help not only in establishing diagnosis and prognosis but potentially serve as targets for modern therapeutic approaches in autoimmune diseases. Orv Hetil. 2019; 160(15): 563-572.

CD69 enhances immunosuppressive function of regulatory T-cells and attenuates colitis by prompting IL-10 production

Foxp3+ regulatory T cells (Tregs) can inhibit immune responses and maintain immune tolerance by secreting immunosuppressive TGF-β1 and IL-10. However, the efficiency of Tregs become the major obstacle to their use for immunotherapy. In this study, we investigated the relevance of the C-type lectin receptor CD69 to the suppressive function. Compared to CD4+Foxp3+CD69− Tregs (CD69− Tregs), CD4+Foxp3+CD69+ Tregs (CD69+ Tregs) displayed stronger ability to maintain immune tolerance. CD69+ Tregs expressed higher levels of suppression-associated markers such as CTLA-4, ICOS, CD38 and GITR, and secreted higher levels of IL-10 but not TGF-β1. CD69+ Tregs from Il10+/+ rather than Il10−/− mice significantly inhibit the proliferation of CD4+ T cells. CD69 over-expression stimulated higher levels of IL-10 and c-Maf expression, which was compromised by silencing of STAT3 or STAT5. In addition, the direct interaction of STAT3 with the c-Maf promoter was detected in cells with CD69 over-expression. Moreover, adoptive transfer of CD69+ Tregs but not CD69−Tregs or CD69+ Tregs deficient in IL-10 dramatically prevented the development of inflammatory bowel disease (IBD) in mice. Taken together, CD69 is important to the suppressive function of Tregs by promoting IL-10 production. CD69+ Tregs have the potential to develop new therapeutic approach for autoimmune diseases like IBD.

Development of a murine model resembling human lupus in mice parasitized with Trichinella spiralis

Abstract Deregulation of Th1 and Th17 immune responses is fundamental in the development of autoimmune diseases, like Systemic Lupus Erythematosus that is a chronic inflammatory autoimmune disease characterized by the production of autoantibodies that cause inflammation and damage to different organs. New therapeutic approaches for autoimmune diseases have been based on the fact that nematodes such as Trichinella spiralis decrease the inflammatory response by inducing the production of anti-inflammatory cytokines, which are potent modulators of T cell function. Recent studies have shown that the proteins secreted by T. spiralis, or the infection itself, induce a polarized Th2/Treg response and the production of regulatory cytokines, which are associated with the amelioration of autoimmune diseases such as colitis, respiratory tract inflammation, type 1 diabetes and experimental autoimmune encephalomyelitis. In this work, mice were infected and, after the life cycle was completed, a procedure to develop lupus was performed. The level of autoantibodies and antibodies anti-Trichinella were detected as well as the levels of Th1 and Th2 cytokines. Here, we show the relevance of studying the immune response in a murine model resembling the human lupus in the presence of T. spiralis muscular larvae, because it provides new information on the immunoregulation of lupus and reveals the effect on its progression.

The role of Syk in peripheral T cells

The aim of this study was to understand how Syk affects peripheral T cell function. T cells from Syk−/− chimeric mice and DR1 Sykfl/fl CD4cre conditional mice gave strong CD3-induced Th1, Th2, and Th17 cytokine responses. However, an altered peptide ligand (APL) of human CII (256–276) with two substitutions (F263N, E266D), also called A12, elicited only Th2 cytokine responses from Sykfl/fl T cells but not Sykfl/fl-CD4cre T cells. Western blots revealed a marked increase in the phosphorylation of Syk, JNK and p38 upon A12/DR1 activation in WT or Sykfl/fl T cells but not in Sykfl/flCD4-cre cells. We demonstrate that Syk is required for the APL- induction of suppressive cytokines. Chemical Syk inhibitors blocked activation of GATA-3 by peptide A12/DR1. In conclusion, this study provides novel insights into the role that Syk plays in directing T cell activity, and may shape therapeutic approaches for autoimmune diseases.

The IL-10/STAT3 axis: Contributions to immune tolerance by thymus and peripherally derived regulatory T-cells.

The signal transducer and activator of transcription (STAT) proteins are important mediators for the integration of extrinsic signals provided by cytokines and hormones and thereby adapt cellular processes to their surroundings. In the past decade, the involvement of STAT3 in the regulation of T-cell responses has become a topic of increasing interest. STAT3 is activated in response to multiple cytokines, many of which have been shown to influence T-cell responses. Interestingly, many of these factors have been described with apparent opposing roles, such as the highly pro-inflammatory potency of IL-6 and the anti-inflammatory properties of IL-10, thus raising the possibility that STAT3 signaling may fulfill diverse roles in CD4+ T-cells. Here, we review the contribution of STAT3 to the induction and function of both peripherally induced as well as thymus-derived regulatory T-cells. Indeed, experimental approaches as well as studies of human patients suffering from e.g. Job's (hyper IgE) syndrome or inflammatory bowel disease (IBD) have now established a clear-cut role for the IL-10/STAT3 axis in immune tolerance; further understanding of these processes could lead to novel therapeutic approaches for autoimmune diseases.

Setting the target for pemphigus vulgaris therapy.

Despite the rising incidence of autoimmunity, therapeutic options for patients with autoimmune disease still rely on decades-old immunosuppressive strategies that risk severe and potentially fatal complications. Thus, novel therapeutic approaches for autoimmune diseases are greatly needed in order to minimize treatment-related toxicity. Such strategies would ideally target only the autoreactive immune components to preserve beneficial immunity. Here, we review how several decades of basic, translational, and clinical research on the immunology of pemphigus vulgaris (PV), an autoantibody-mediated skin disease, have enabled the development of targeted immunotherapeutic strategies. We discuss research to elucidate the pathophysiology of PV and how the knowledge afforded by these studies has led to the preclinical and clinical testing of targeted approaches to neutralize autoantibodies, to induce antigen-specific tolerance, and to specifically eliminate autoreactive B cells in PV.

EFFECT OF EDEM1 OVEREXPRESSION ON THE GENERATION AND ASSEMBLY OF MAJOR HISTOCOMPATIBILITY COMPLEXES

Background. A better understanding of the role of endoplasmic reticulum degradation-enhancing alpha-mannosidase – like protein 1 (EDEM1) in endoplasmic reticulum associated degradation (ERAD) may open new therapeutic approaches in autoimmune diseases. Aim. To study ERAD and EDEM1 in the generation and assembly of MHC I and the potential role in the pathophysiology of autoimmune diseases. Materials and methods. HEK293T cell line (human embrionic kidney cells), A375 cell line (amelanotic melanoma cells) and THP-1 cell line (leukemic monocytes used both as undifferentiated and differentiated) underwent transient transfection with EDEM1 and mock transfection with pTriEx. Western blot experiments assessed the total cellular MHC I levels in cell lysates, while expression on the cellular surface was quantified by flow cytometry of fixed cells. Results were analysed using the FACS Calibur and CellQuest Pro dedicated software. Experiments were done twice with duplicate probes for the Western blot assay and triplicate probes were used for flow cytometry. GraphPad Prism was used for data analysis. Results. MHC I plasma membrane routing and expression was similar in HEK293T and A375 both in mock transfected and non-transfected cells. Western blot assay for EDEM1 transfected cells showed bands corresponding to the total MHC I that migrated at 42kDa mass in non-transfected and mock transfected Hek293T, A375 and undifferentiated THP-1 cells. Mock transfected differentiated THP-1 cells showed a reduction of total MHC I. EDEM1 transfected Hek293T, A375 and undifferentiated THP-1 cells displayed higher levels of total MHC I, while differentiated THP-1 cells showed a marked reduction. Flow cytometry assay showed significantly reduced cell surface MHC I levels in Hek293T cell line. We observed a modest reduction of MHC I complexes on the cellular surface in undifferentiated THP-1 EDEM1 transfected cells, while there was no significant change in the A375 EDEM1 transfected cell line, as well as the differentiated THP-1 EDEM1 transfected cells. Conclusion. The impact of ERAD’s EDEM1 in MHC I reduction may have an important role in autoimmune disease, making ERAD an interesting therapeutic target.