Regulation Of Autoimmune Diseases Research Articles

The PTPN22 as Master Regulation in Autoimmune Diseases and Its Susceptibility to Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a long-term autoimmune condition that causes joint inflammation, resulting in pain, tenderness, expansion, and even joint malformation. It mostly causes inflammation and thickening of the synovium, the membrane that lines the joints. Joint erosion, cartilage breakdown, and function loss are all possible outcomes of RA over time. Though it can affect any joint in the body, it usually affects the smaller joints in the hands and feet. A significant role can be played by genetic ability in the progress of rheumatoid arthritis. The review's subject, "PTPN22" (sometimes referred to as "LYP in humans or PEP in mice"), is the typical non receptor PTP belonging to the proline rich subgroup of Type I. PTPN22 is a "major negative regulator of T-cell receptor (TCR) signal transduction" which is mostly express in the immune cells. Interestingly, a mutation in this gene has been related to the onset of many autoimmune disorders. Several genetic variants have been identified that contribute to the risk of developing RA, including rs2476601. This review discussed the PTPN22 as master regulation of immune system and the role of rs2476601 in RA.

Light-activated extracellular matrix microcarriers with engineered MSCs loading for autoimmune psoriasis treatment

The stem-cell-therapy supported by hydrogel microcarriers has shown potentials in the regulation of autoimmune diseases. Trends in this field focus on enhancing the viability and the delivery controllability of stem cells. Herein, we proposed novel fish extracellular matrix (ECM) microcarriers loaded with mesenchymal stem cells (MSCs) that secrete programmed cell death-ligand 1 (PD-L1) for autoimmune disease treatment. We developed an optimized acellular method to extract the fish skin ECM, followed by mixing it with ruthenium (Ru)/sodium persulfate (SPS) to generate light-activated ECM bio-ink. By introducing this bio-ink into a droplet microfluidic device, porous ECM microcarriers could be generated after in-situ photocrosslinking. With the decoration of polydopamine, MSCs with enhanced PD-L1 expression by lentivirus transfection can adhere well to these ECM microcarriers, serving as ideal candidate for stem-cell-therapy. We have demonstrated that the engineered MSCs delivered through the ECM microcarriers have a higher survival rate compared with direct injection. Besides, these MSCs-loaded microcarriers can effectively inhibit the epidermis thickening and lower the PASI score in an in vivo psoriasis model. Therefore, the proposed engineered MSCs-loaded ECM microcarriers are anticipated to pave the way for promising clinical treatments of autoimmune psoriasis diseases.

3D genome organization and epigenetic regulation in autoimmune diseases.

Three-dimensional (3D) genomics is an emerging field of research that investigates the relationship between gene regulatory function and the spatial structure of chromatin. Chromatin folding can be studied using chromosome conformation capture (3C) technology and 3C-based derivative sequencing technologies, including chromosome conformation capture-on-chip (4C), chromosome conformation capture carbon copy (5C), and high-throughput chromosome conformation capture (Hi-C), which allow scientists to capture 3D conformations from a single site to the entire genome. A comprehensive analysis of the relationships between various regulatory components and gene function also requires the integration of multi-omics data such as genomics, transcriptomics, and epigenomics. 3D genome folding is involved in immune cell differentiation, activation, and dysfunction and participates in a wide range of diseases, including autoimmune diseases. We describe hierarchical 3D chromatin organization in this review and conclude with characteristics of C-techniques and multi-omics applications of the 3D genome. In addition, we describe the relationship between 3D genome structure and the differentiation and maturation of immune cells and address how changes in chromosome folding contribute to autoimmune diseases.

Endogenously produced catecholamines improve the regulatory function of TLR9-activated B cells.

The sympathetic nervous system (SNS) contributes to immune balance by promoting anti-inflammatory B cells. However, whether B cells possess a self-regulating mechanism by which they modulate regulatory B cell (Breg) function is not well understood. In this study, we investigated the ability of B cells to synthesize their own catecholamines upon stimulation with different B cell activators and found that expression of the enzyme tyrosine hydroxylase (TH), required to generate catecholamines, is up-regulated by Toll-like receptor (TLR)9. This TLR9-dependent expression of TH correlated with up-regulation of adrenergic receptors (ADRs), enhanced interleukin (IL)-10 production, and overexpression of the co-inhibitory ligands programmed death ligand 1 (PD-L1) and Fas ligand (FasL). Moreover, concomitant stimulation of ß1-3-ADRs together with a B cell receptor (BCR)/TLR9 stimulus clearly enhances the anti-inflammatory potential of Bregs to suppress CD4 T cells, a crucial population in the pathogenesis of autoimmune diseases, like rheumatoid arthritis (RA). Furthermore, TH up-regulation was also demonstrated in B cells during the course of collagen-induced arthritis (CIA), a mouse model for the investigation of RA. In conclusion, our data show that B cells possess an autonomous mechanism to modulate their regulatory function in an autocrine and/or paracrine manner. These findings help to better understand the function of B cells in the regulation of autoimmune diseases and the interplay of SNS.

An update on epigenetic regulation in autoimmune diseases

Autoimmune diseases (AIDs) generally manifest as chronic immune disorders characterized by significant heterogeneity and complex symptoms. The discordant incidence of AIDs between monozygotic twins guided people to attach importance to environmental factors. Epigenetics is one of the major ways to be influenced, some of them can even occur years before clinical diagnosis. With the advent of high-throughput omics times, the mysterious veil of epigenetic modification in AIDs has been gradually unraveled, and some progress has been made in utilizing it as indicators of diagnosis and disease activity. For example, the hypomethylated IFI44L promoter in diagnosing systematic lupus erythematosus (SLE). More recently, newly identified noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are also believed to be involved in the etiology of AIDs while the initial factor behind those epigenetic alterations can be diverse from metabolism to microbiota. Update and comprehensive insights into epigenetics in AIDs can help us understand the pathogenesis and further orchestrate it to benefit patients in the future. Therefore, we reviewed the latest epigenetic findings in SLE, rheumatoid arthritis (RA), Type 1 diabetes (T1D), systemic sclerosis (SSc) primarily from cellular levels.

Association of Inherited Genotype and Severity of Clinical Presentation in Subjects with Verified Pas III Disorder.

Background:Polyglandular autoimmune syndrome type III (PAS III) is combination two most common autoimmune disease: Diabetes mellytus type 1 (DM1) and autoimmune thyroid disease (AITD).Objectives:The aims of the study were a) to define conection between polymorphism of CTLA-4 gene, rs 231775 with PAS III; b) to establish the conection of inherited genotype with severity of clinical features; and c) to estimate the rate of risk for severe clinical presentation among subgroups in study population.Methods:This research included 50 subjects with diagnosed PAS III syndrome, wich are on treatment in clinic for Nuclear medicine and andocrinology KCUS. As methods of research has used: hystory of disesase AND clinical examination. As material is used blood sample. From blood sample DNA was isolated withn Qiamp- DNA-mini kit, with accopanied protocol.Results:In our study, 50 patients with polyglandular autoimmune syndrome type III (PAS III) were examined, and in the study population had 26 female subjects and 24 male subjects. The average age of the participants was 31.64 years, and in the subgroups: group GWT (G-wild type) the average age was 30.20 years, group GM (G-mutated) 32.40 years and group GH (G-heterozygote) 30 , 60 years. Using the Chi-square test, the association between the polymorphism rs231775 and PAS-III was demonstrated, x2 (2.100) = 18.258, where p < 0.0001. Using the Chi-square test, the association between the rs231775 polymorphism and the severity of the clinical picture, x2 (2.50) = 8.531, where p< 0.0140 was proved. The CTLA-4 rs231775 genotypes were also assessed for disease severity.Conclusion:This study suggests that CTLA-4 expression plays a key role in balancing the immune system as well as the response against one’s own tissues, and thus in the regulation of autoimmune diseases.

Elevated Expression of the Long Noncoding RNA MAFTRR in Patients with Hashimoto's Thyroiditis.

Background Long noncoding RNAs (lncRNAs) represent an important novel class of noncoding RNA molecule greater than 200 nucleotides that play a key role in the regulation of autoimmune diseases. Previous studies have demonstrated that MAFTRR (MAF transcriptional regulator RNA) regulated Th1 cells differentiation by inhibiting the expression of MAF in activated CD4+ T cells. However, the effect of MAFTRR on the pathogenesis of Hashimoto's thyroiditis (HT) remains unclear. This research was aimed at investigating the expression of MAFTRR in Hashimoto's thyroiditis (HT) as well as the correlation between MAFTRR and Th1 cells. Methods Thirty-eight HT patients and thirty-eight healthy controls were enrolled in the study. The proportion of Th1 cells and CD8+IFN-γ+ T cells in peripheral blood mononuclear cells (PBMCs) from these specimens was determined by flow cytometric analysis. The transcript levels of MAFTRR, MAF, and IFNG in PBMCs and thyroid glands were detected by quantitative real-time PCR. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the potential value of MAFTRR in the HT patients. Results We found that the proportion of circulating Th1 cells and the transcript levels of IFNG were increased in peripheral blood of the HT patients. The transcript levels of MAFTRR were significantly increased in the HT patients and positively correlated with the percentage of Th1 cells and serum levels of antithyroglobulin antibody and antithyroperoxidase antibody. The transcript levels of MAF, a transcription factor that inhibits Th1 cells activity and IFN-γ production, were attenuated in PBMCs from the HT patients. The transcript levels of IFNG had positive and inverse correlations with MAFTRR and MAF expression in PBMCs from the HT patients, respectively. Additionally, a significantly positive correlation between upregulated MAFTRR expression and augmented IFNG expression was revealed in thyroid tissues from the HT patients. ROC curve suggested that MAFTRR could potentially differentiate the HT patients from healthy controls. Conclusion MAFTRR is significantly augmented in the HT patients and may contribute to the pathogenic role of the Th1 cells response in HT.

CircRNA-binding protein site prediction based on multi-view deep learning, subspace learning and multi-view classifier.

Circular RNAs (circRNAs) generally bind to RNA-binding proteins (RBPs) to play an important role in the regulation of autoimmune diseases. Thus, it is crucial to study the binding sites of RBPs on circRNAs. Although many methods, including traditional machine learning and deep learning, have been developed to predict the interactions between RNAs and RBPs, and most of them are focused on linear RNAs. At present, few studies have been done on the binding relationships between circRNAs and RBPs. Thus, in-depth research is urgently needed. In the existing circRNA-RBP binding site prediction methods, circRNA sequences are the main research subjects, but the relevant characteristics of circRNAs have not been fully exploited, such as the structure and composition information of circRNA sequences. Some methods have extracted different views to construct recognition models, but how to efficiently use the multi-view data to construct recognition models is still not well studied. Considering the above problems, this paper proposes a multi-view classification method called DMSK based on multi-view deep learning, subspace learning and multi-view classifier for the identification of circRNA-RBP interaction sites. In the DMSK method, first, we converted circRNA sequences into pseudo-amino acid sequences and pseudo-dipeptide components for extracting high-dimensional sequence features and component features of circRNAs, respectively. Then, the structure prediction method RNAfold was used to predict the secondary structure of the RNA sequences, and the sequence embedding model was used to extract the context-dependent features. Next, we fed the above four views' raw features to a hybrid network, which is composed of a convolutional neural network and a long short-term memory network, to obtain the deep features of circRNAs. Furthermore, we used view-weighted generalized canonical correlation analysis to extract four views' common features by subspace learning. Finally, the learned subspace common features and multi-view deep features were fed to train the downstream multi-view TSK fuzzy system to construct a fuzzy rule and fuzzy inference-based multi-view classifier. The trained classifier was used to predict the specific positions of the RBP binding sites on the circRNAs. The experiments show that the prediction performance of the proposed method DMSK has been improved compared with the existing methods. The code and dataset of this study are available at https://github.com/Rebecca3150/DMSK.

Immunosuppressive Regulation of Dendritic Cells and T Cells in Allergic Rhinitis by Semaphorin 3A.

Semaphrin3A (Sema3A) was found to play a major role in immune regulation in autoimmune diseases and to be of importance in allergic disease. However, the effect of Sema3A on allergic rhinitis (AR) is not fully clear. We sought to elucidate the effects of Sema3A on the regulation of dendritic cells (DCs) and naive CD4+ T cells in AR. The expression of Sema3A in nasal mucosa was measured by immunohistochemical staining and western blotting. Human peripheral blood mononuclear cells were separated by the Ficoll-Hypaque method. DCs and naive CD4+ T cells were purified by magnetic selection. A human Sema3A Fc chimera was added to DCs and naive CD4+ T cells in vitro to evaluate the effect of Sema3A on the function of DCs and T cells. Labeling T cells with CFSE was used to determine cell proliferation. Flow cytometry was used to detect the DC maturation markers (CD40 and CD83) and T helper 17 (Th17) and regulatory T cell (Treg) percentages. ELISA was used to detect the IL10, IL17, IL4, and IFNγ cytokine levels. The expression of Sema3A in AR inferior turbinate tissue was lower than that in healthy control tissue. Compared with healthy control DCs, AR DCs showed decreased levels of the DC maturation markers CD40 and CD83 after Sema3A treatment. Furthermore, Sema3A decreased naive CD4+ T cell proliferation in AR. In addition, Sema3A increased the percentage of Tregs but had no obvious effect on Th17 cells. Moreover, Sema3A significantly increased levels of IL10 and IFNγ, and decreased level of IL4, but had no obvious effect on level of IL17. AR presented with low expression of Sema3A in nasal mucosa, and Sema3A could decrease DC maturation, T cell proliferation, and Treg polarization.

Arginase 1+ IL‐10+ polymorphonuclear myeloid‐derived suppressor cells are elevated in patients with active pemphigus and correlate with an increased Th2/Th1 response

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells, which are characterized by their capability to suppress T-cell responses. While MDSCs have been traditionally associated with cancer diseases, their role as regulators of autoimmune diseases is emerging. Pemphigus is a chronic autoimmune blistering skin disease characterized by dysregulated T-cell responses and autoantibody production. The role of MDSCs in pemphigus disease has not been defined yet. The aim of this study was to characterize MDSCs in pemphigus patients and to dissect their relationship with CD4+ T-cell subsets and clinical disease assessments. For this purpose, we performed a cross-sectional analysis of 20 patients with pemphigus. Our results indicate that a population of CD66b+ CD11b+ polymorphonuclear-like MDSCs (PMN-MDSCs) is expanded in the peripheral blood mononuclear cell fraction of pemphigus patients compared to age-matched healthy donors. These PMN-MDSCs have the capability of suppressing allogeneic T-cell proliferation in vitro and show increased expression of characteristic effector molecules such as arginase I and interleukin-10. We further demonstrate that PMN-MDSCs are especially expanded in patients with active pemphigus, but not in patients in remission. Moreover, MDSC frequencies correlate with an increased Th2/Th1 cell ratio. In conclusion, the identification of a functional PMN-MDSC population suggests a possible role of these cells as regulators of Th cell responses in pemphigus.

TLR9 stimulation by the gut microbiota promotes tissue-specific immunosuppression in autoimmune-prone MRL/lpr mice

Abstract To investigate the ability of gut microbiota to modify immune regulation in autoimmune disease, we treated lupus-prone mice with oral vancomycin prior to disease development, and subsequently administered bacterial DNA isolated from commensal bacteria. Vancomycin given prior to disease initiation promotes exacerbation of autoimmune disease, likely due to a decrease in the frequency of B regulatory (Breg) cells, whereas vancomycin given after autoimmune disease onset has suppressive effects on disease phenotype in MRL/lpr mice. Bacterial DNA administration during the pre-disease stage promoted Breg cell production and suppressed autoimmune disease parameters in MRL/lpr mice. Further, we showed that activation of toll-like receptor 9 (TLR9) on B cells was involved in the suppressive effects of bacterial DNA seen in the MRL/lpr mouse model. We found that during the pre-disease period, joint treatment with vancomycin and oral administration of a TLR9 specific agonist, ODN 1826, promoted Breg cells in the lamina propria, increased total CD8+ T cells and effector memory CD44 expressingCD8+ T cells in the spleen, and suppressed Th17 and IFNγ producing CD4+ T cells in the mesenteric lymph nodes. Oral ODN 1826 administration also increased the Treg/Th17 ratio in the mesenteric lymph nodes. The alterations in suppressive vs. proinflammatory cell phenotypes by oral exposure to ODN 1826 suggests that the suppressive effects of bacterial DNA from the gut microbiota are modulated through TLR9 activation in a tissue-specific manner.

Role of indoleamine 2,3-dioxygenase in testicular immune-privilege

Male meiotic germ cell including the spermatozoa represent a great challenge to the immune system, as they appear long after the establishment of normal immune tolerance mechanisms. The capacity of the testes to tolerate autoantigenic germ cells as well as survival of allogeneic organ engrafted in the testicular interstitium have led to consider the testis an immunologically privileged site. Disruption of this immune privilege following trauma, tumor, or autoimmune orchitis often results in male infertility. Strong evidence indicates that indoleamine 2,3-dioxygenase (IDO) has been implicated in fetal and allograft tolerance, tumor immune resistance, and regulation of autoimmune diseases. IDO and tryptophan 2,3-dioxygenase (TDO) catalyze the same rate-limiting step of tryptophan metabolism along a common pathway, which leads to tryptophan starvation and generation of catabolites collectively known as kynurenines. However, the relevance of tryptophan metabolism in testis pathophysiology has not yet been explored. Here we assessed the in vivo role of IDO/TDO in experimental autoimmune orchitis (EAO), a model of autoimmune testicular inflammation and immunologically impaired spermatogenesis. EAO was induced in adult Wistar rats with testicular homogenate and adjuvants. Control (C) rats injected with saline and adjuvants and normal untreated rats (N) were also studied. mRNA expression of IDO decreased in whole testes and in isolated Sertoli cells during EAO. TDO and IDO localization and level of expression in the testis were analyzed by immunostaining and Western blot. TDO is expressed in granulomas from EAO rats, and similar protein levels were observed in N, C, and EAO groups. IDO was detected in mononuclear and endothelial cells and reduced IDO expression was detected in EAO group compared to N and C rats. This phenomenon was concomitant with a significant reduction of IDO activity in EAO testis measured by tryptophan and kynurenine concentrations (HPLC). Finally, in vivo inhibition of IDO with 1-methyl-tryptophan increased severity of the disease, demonstrating down regulation of IDO-based tolerance when testicular immune regulation was disrupted. We present evidence that an IDO-based mechanism is involved in testicular immune privilege.

Potential role of IL-37 signaling pathway in feedback regulation of autoimmune Hashimoto thyroiditis.

IL-37, the anti-inflammatory cytokine of the IL-1 family, plays several key roles in the regulation of autoimmune diseases. Yet, its role in Hashimoto's thyroiditis (HT) is not clear. In the present study, we found that, in tissues from HT patients, most of the follicular epithelial cells were positive for both IL-37 and single Ig IL-1-related receptor (SIGIRR) by immunohistochemical staining, while the infiltrating lymphocytes and other inflammatory cells hardly expressed any. Meanwhile, mRNA expression levels of IL-37 in peripheral blood mononuclear cells (PBMC) of HT patients were significantly higher than those in normal controls measured by quantitative real-time PCR. Finally, we studied the possible role of IL-37 in IFN-γ-stimulated rat FRTL-5 cells. The results showed that IL-1β, TNF-α, and MCP-1 mRNA levels were significantly decreased, while the expression of IL-4 mRNA was dramatically up-regulated in IFN-γ-stimulated rat thyroid cell line FRTL-5 pre-treated with IL-37. The current study, for the first time, demonstrated that the IL-37 network is involved in Hashimoto's thyroiditis, and IL-37 signaling pathway may ameliorate the excessive autoimmune responses in this chronic lymphocytic thyroiditis.

Association of HLA-G + 3142G > C gene polymorphism and toll-like receptor-9 serum level in systemic lupus erythematosus patients

BackgroundHuman leukocyte antigen-G (HLA-G) and Toll-like receptor-9 (TLR-9) play a role in the regulation of autoimmune diseases and inflammatory processes. Aim of the studyTo detect the HLA-G + 3142G > C gene polymorphism that associated with the susceptibility to SLE patients and associated with Hepatitis B infection and TLR-9 serum level. Patients and methodsThis study was done on 75 SLE patients and 75 healthy control groups. Genotyping of HLA-G + 3142G > C were detected by PCR and PCR-RFLP methods. In addition to the estimation of Hepatitis B surface (HBs) antigen status by immunochromatography technique and TLR-9 serum level by ELISA technique. ResultsThe HLA-G + 3142G > C gene polymorphism between the SLE patients and controls in CC, CG and GG genotyping (5.33% vs. 45.34%; OR = 0.07; P = 1.0 × 10−8, 21.33% vs. 37.34%; OR = 0.46; P = 0.048, 73.33% vs. 17.33%, OR = 47.45; P = 4.5 × 10−12 respectively). In addition, there was a significant increase frequency of G allele in SLE patients compared to controls (0.84 vs. 0.36). While the C allele showed a significantly decreased frequency in patients compared to controls (0.16 vs. 0.64). The seropositive status of HBs antigen showed no significant difference between the SLE patients' group and controls (OR = 7.3, 95%CI = 0.38–140.81). While the mean of TLR-9 serum level was significantly increased in SLE patients' group compared to the control group (399.9 ± 66.7 pg/ml vs. 122.2 ± 28.5 pg/ml; p ≤ 0.05). ConclusionThe HLA-G + 3142G > C homozygous genotype GG and G allele were more associated with SLE patients. The HBs antigen showed no significant association with SLE patients. While, TLR-9 serum level showed a significant association with SLE development.

Regulation of autoimmune disease by the E3 ubiquitin ligase Itch

Itch is a HECT type E3 ubiquitin ligase that is required to prevent the development of autoimmune disease in both mice and humans. Itch is expressed in most mammalian cell types, and, based on published data, it regulates many cellular pathways ranging from T cell differentiation to liver tumorigenesis. Since 1998, when Itch was first discovered, hundreds of publications have described mechanisms through which Itch controls various biologic activities in both immune and non-immune cells. Other studies have provided insight into how Itch catalytic activity is regulated. However, while autoimmunity is the primary clinical feature that occurs in both mice and humans lacking Itch, and Itch control of immune cell function has been well-studied, it remains unclear how Itch prevents the emergence of autoimmune disease. In this review, we explore recent discoveries that advance our understanding of how Itch regulates immune cell biology, and the extent to which these clarify how Itch prevents autoimmune disease. Additionally, we discuss how molecular regulators of Itch impact its ability to control these processes, as this may provide clues on how to therapeutically target Itch to treat patients with autoimmune disease.

Novel regulatory Th17 cells and regulatory B cells in modulating autoimmune diseases

Pathogenic lymphocytes aberrantly recognize and mount an immune response against self-antigens, leading to the destruction of healthy cells, tissues and organs. Recent studies have shown that both B and T lymphocytes contribute to the development, prevention and modulation of various autoimmune diseases. Regulatory T and B cell subsets appear to play a prominent role in the prevention of autoimmune diseases. The recent identification of novel regulatory Th17 cells, termed as Treg17 cells, has expanded the scope of regulatory T lymphocytes (Treg cells) in the prevention of autoimmune diseases. Similarly, novel regulatory B cell subsets, termed as Breg cells, acting on their own or by inducing Treg cells have extended the role of B lymphocytes in the prevention and regulation of autoimmune diseases. We suggest that Treg17 cells and Breg cells have an important immunoregulatory role in autoimmune diseases.

MicroRNA-448 promotes multiple sclerosis development through induction of Th17 response through targeting protein tyrosine phosphatase non-receptor type 2 (PTPN2)

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system, and its pathogenesis remains largely unclear. Much attention has been paid to the role of microRNAs (miRs) in regulation of autoimmune disease. Here, we found, for the first time, that miR-448 expression was significantly increased in periphery blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) of patients with MS, and its expression positively correlated with the disease severity. We further demonstrated that CD4+ T cells, especially the Th17 lineage, were the major source of miR-448 expression. Using gain- and loss-of-function approaches, we further verified that miR-448 could enhance Th17 differentiation, characterized by up-regulated expression levels of IL-17A and RORγt. Interleukin (IL)-1β as a potent driver of pathogenic Th17 cells was able to strongly induce miR-448 expression in CD4+ T cells through activating NF-κB pathway. Additionally, we identified that miR-448 directly targeted protein tyrosine phosphatase non-receptor type 2 (PTPN2), which has been known as an anti-inflammatory player with capacity to suppress Th17 differentiation. We also observed markedly decreased expression of PTPN2 in PBMC and CSF of MS patients. Our results suggest that miR-448 might promote Th17 differentiation in MS and thus aggravate the disease through inhibiting PTPN2.

DEPTOR-mTOR Signaling Is Critical for Lipid Metabolism and Inflammation Homeostasis of Lymphocytes in Human PBMC Culture.

Abnormal immune response of the body against substances and tissues causes autoimmune diseases, such as polymyositis, dermatomyositis, and rheumatoid arthritis. Irregular lipid metabolism and inflammation may be a significant cause of autoimmune diseases. Although much progress has been made, mechanisms of initiation and proceeding of metabolic and inflammatory regulation in autoimmune disease have not been well-defined. And novel markers for the detection and therapy of autoimmune disease are urgent. mTOR signaling is a central regulator of extracellular metabolic and inflammatory processes, while DEP domain-containing mTOR-interacting protein (DEPTOR) is a natural inhibitor of mTOR. Here, we report that overexpression of DEPTOR reduces mTORC1 activity in lymphocytes of human peripheral blood mononuclear cells (PBMCs). Combination of DEPTOR overexpression and mTORC2/AKT inhibitors effectively inhibits lipogenesis and inflammation in lymphocytes of PBMC culture. Moreover, DEPTOR knockdown activates mTORC1 and increases lipogenesis and inflammations. Our findings provide a deep insight into the relationship between lipid metabolism and inflammations via DEPTOR-mTOR pathway and imply that DEPTOR-mTOR in lymphocytes of PBMC culture has the potential to be as biomarkers for the detection and therapies of autoimmune diseases.

Effects of Rituximab and Dexamethasone on Regulatory and Pro-Inflammatory B-Cell Subsets in Patients with Primary Immune Thrombocytopenia

BackgroundB-cell depletion with rituximab (RTX) is widely accepted as first- or second-line therapy in primary immune thrombocytopenia (ITP), but it is still unclear how RTX mediates its positive effect in ITP patients. RTX has been reported to induce a reduced titer of platelet antibodies. However, this finding is inconsistent and other B-cell functions, such as the ability to secrete cytokines or to function as antigen-presenting cells for T cells, may be involved in the pathogenesis of ITP. Evidence suggests that B cells participate in the regulation of autoimmune diseases by virtue of their ability to produce the regulatory cytokines interleukin (IL)-10, IL-35, or transforming growth factor β. The various functions of B cells involved in the pathogenesis of autoimmune diseases can in part be deducted by their phenotype as recognized by measurement of specific surface markers and cytokine secretion.Materials and MethodsWe previously conducted a trial involving 137 newly diagnosed adult ITP patients randomized to treatment with RTX (375 mg/m2/week for 4 weeks) + dexamethasone (DXM) (40 mg/day for 4 days repeated up to 6 cycles) or DXM monotherapy. From this cohort, we identified 16 patients with available samples of peripheral blood mononuclear cells (PBMCs) at baseline and 12 months after treatment; 9 patients from the RTX+DXM group, 7 patients from the DXM group. Seven anonymous blood donors served as healthy controls.PBMCs were incubated for 18 h at 37°C under 5% CO2 in RPMI-1640 containing 10% (v/v) serum from healthy blood group AB donors, either alone or stimulated with 10 µg/ml CpG oligodeoxynucleotides. Expression of the cell-surface markers CD5, CD27, CD25 and CD19, and intracellular content of IL-6 and IL-10 were measured by flow cytometry.ResultsAll patients responded to therapy and were in complete or partial remission at 12 months. Patient characteristics are listed in table I.We observed a significant increase in the proportion of CD5+ B cells 12 months after treatment with RTX+DXM compared to baseline (p < 0.01, Fig. 1A). The percentage of CD27+ memory B cells was significantly decreased at 12 months compared to baseline in patients receiving RTX+DXM (p < 0.05, Fig. 1B), and there was an inverse correlation between platelet numbers and the proportion of CD27+ B cells (R = -0.71; p < 0.05). The proportion of CD25+ B cells tended to decrease in patients treated with RTX+DXM, and was lower at 12 months than in patients treated with DMX only (p < 0.05, Fig 1C).PBMCs from ITP patients contained a lower proportion of IL-10+ B cells (p < 0.01) as well as a lower proportion of B cells producing IL-6 (p < 0.01) at baseline than PBMCs from healthy controls. At 12 months the low proportions had normalized in both treatment groups (Fig. 2).ConclusionB cells from ITP patients treated with RTX+DXM contained a high proportion of CD5+ B cells and low proportions of CD25+ and CD27+ B cells. Before treatment, B cells from ITP patients contained low frequencies of IL-10+ and IL-6+ B cells. Treatment with RTX + DXM or DXM alone reverted these aberrancies to normal. The increase in IL-10+ B cells as well as CD5+ B cells, which may represent overlapping subsets, is compatible with induction of Bregs and may support Treg development. Given the role of CD5+ B cells in maintenance of tolerance, the high frequency of these cells, which has also been observed after RTX therapy in rheumatoid arthritis, is compatible with amelioration of disease. [Display omitted] [Display omitted] [Display omitted] DisclosuresGudbrandsdottir:GSK: Research Funding; Amgen: Research Funding.

Elimination of Granulocytic Myeloid‐Derived Suppressor Cells in Lupus‐Prone Mice Linked to Reactive Oxygen Species–Dependent Extracellular Trap Formation

ObjectiveEmerging evidence supports a crucial role of myeloid‐derived suppressor cells (MDSCs) in the regulation of autoimmune diseases. However, their role in systemic lupus erythematosus (SLE) remains unknown. This study sought to address the role of MDSCs in the pathogenesis of SLE.Methods MDSCs from (NZB × NZW)F1 lupus‐prone mice were assessed for phenotype by flow cytometry, and the function of MDSCs was analyzed by in vitro T cell proliferation assay and real‐time quantitative polymerase chain reaction. Extracellular trap (ET) formation was evaluated by immunofluorescence and confocal microscopy. The production of reactive oxygen species (ROS) by Ly‐6G+ cells was determined by fluorescence‐activated cell sorting analysis.ResultsExpansion of MDSCs was impaired and the function of MDSCs was defective in the lymphoid organs of (NZB × NZW)F1 lupus‐prone mice with established disease, in which involvement of predominantly the granulocytic MDSC (G‐MDSC) cell subset was observed. More specifically, the results showed that increased elimination of G‐MDSCs, driven by the inflammatory milieu of lupus, could be attributed to ET formation, and that cytokines, such as interferon‐α (IFNα), IFNγ, and interleukin‐6, play a role in this process. Induction of ET release by G‐MDSCs was mediated by the production of ROS, since inhibition of ROS generation significantly reduced ET release.ConclusionCollectively, the results of this study reveal that elimination of a crucial regulatory immune cell subset is a feature of the SLE microenvironment. These findings provide new insights into the pathogenetic mechanisms of the disease.