apyrase and Autoimmune-Diseases

Exact causes for autoimmune diseases remain unclear and no cures are available. Breakdown of immunotolerance could set the stage for unfettered immune responses that target self-antigens. Impaired regulatory immune mechanisms could have permissive roles in autoreactivity. Abnormal regulatory immune cell function, therefore, might be a major determinant of the pathogenesis of autoimmune disease. All current treatments are associated with some level of clinical toxicity. Treatment to specifically target dysregulated immunity in these diseases would be a great advance. Extracellular adenosine is a signaling mediator that suppresses inflammation through activation of P1 receptors, most active under pathological conditions. Mounting evidence has linked alterations in the generation of adenosine from extracellular nucleotides by ectonucleotidases, and associated perturbations in purinergic signaling, to the immunological disruption and loss of immunotolerance in autoimmunity. Targeted modulation of the purinergic signaling by either targeting ectonucleotidases or modulating P1 purinergic receptors could therefore restore the balance between autoreactive immune responses; and thereby allow reestablishment of immunotolerance. We review the roles of CD39 and CD73 ectoenzymes in inflammatory states and with the dysregulation of P1 receptor signaling in systemic and organ-specific autoimmunity. Correction of such perturbations could be exploited in potential therapeutic applications.

Topics: Adenosine; Antigens, Neoplasm; Apyrase; Autoimmune Diseases; Humans; Organ Specificity; Receptors, Purinergic P1; Signal Transduction; Tetraspanins

Topics: 5'-Nucleotidase; Adenosine; ADP-ribosyl Cyclase 1; Animals; Antigens, CD; Apyrase; Autoimmune Diseases; Humans

The ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1, or CD39) catalyzes the phosphohydrolysis of extracellular ATP (eATP) and ADP (eADP) released under conditions of inflammatory stress and cell injury. CD39 generates AMP, which is in turn used by the ecto-5'-nucleotidase CD73 to synthesize adenosine. These ectonucleotidases have a major impact on the dynamic equilibrium of proinflammatory eATP and ADP nucleotides versus immunosuppressive adenosine nucleosides. Indeed, CD39 plays a dominant role in the purinergic regulation of inflammation and the immune response because its expression is influenced by genetic and environmental factors. We review the specific role of CD39 in the kinetic regulation of cellular immune responses in the evolution of disease. We focus on the effects of CD39 on T cells and explore potential clinical applications in autoimmunity, chronic infections, and cancer.

Topics: 5'-Nucleotidase; Adenosine; Adenosine Monophosphate; Animals; Antigens, CD; Apyrase; Autoimmune Diseases; Autoimmunity; Gene-Environment Interaction; Humans; Immune Tolerance; Infections; Inflammation; Lymphocyte Activation; Neoplasms; T-Lymphocytes

Autoimmune diseases are characterized by the abnormal immune response against self-tissue, which are caused by the failure of nature immune homeostasis. Nature immune homeostasis represents the normal state of appropriate immune response to nonself-antigen and unresponsiveness to self-antigens. In normal situation, immune homeostasis is regulated by immunosuppressive signal and immunostimulating signal together. Accumulating data have demonstrated that the adenosinergic pathway played key roles in immune suppression and shield body from an excessive inflammatory response. The deficiency of adenosinergic pathway results in the imbalance between the pro- and anti-inflammatory activities. Thus, researchers pay much attention to the role of adenosinergic pathway in autoimmune diseases development. To date, accumulating data have suggested an important role of adenosinergic pathway-related molecules (i.e., CD39, CD73, ADA, adenosine receptors, etc.) in many types of human autoimmune diseases. More importantly, these findings have presented potential value of adenosinergic pathway analysis to be used for autoimmune diseases diagnosis, monitoring and treatment. In this review, we will provide a comprehensive description of the role of adenosinergic pathway in human autoimmune diseases.

Topics: 5'-Nucleotidase; Adenosine; Adenosine Deaminase; Antigens, CD; Apyrase; Autoimmune Diseases; Humans; Immune Tolerance; Immunologic Tests; Immunosuppression Therapy; Molecular Targeted Therapy; Receptors, Purinergic P1; Signal Transduction

Therapeutic manipulation of regulatory T cells (Tregs) has been regarded as a promising approach for the treatment of immune disorders. However, a better understanding of the immunomodulatory mechanisms of Tregs and new safe and effective methods to improve the therapeutic effects of Tregs are highly desired. In this study, we have identified the key roles of a cAMP-adenosine positive feedback loop in the immunomodulatory function of Tregs. Adult male C57BL/6J mice were used for an experimental autoimmune uveitis (EAU) model, Tregs, and uveitogenic T cells (UTs). In established EAU, induced Tregs (iTregs) administration alleviated the inflammatory response. In vitro, iTregs inhibited UTs proliferation and inflammatory cytokine production. Mechanistically, cAMP is partially responsible for iTreg-mediated inhibition on UTs. Importantly, intracellular cAMP regulates CD39 expression and CD39-dependent adenosine production in iTregs, and cAMP directly participates in iTreg-derived adenosine production by a CD39 signaling-independent extracellular cAMP-adenosine pathway. Moreover, extracellular adenosine increases the intracellular cAMP level in Tregs. More importantly, increasing the cAMP level in iTregs before transfer improves their therapeutic efficacy in established EAU. Notably, the cAMP-adenosine loop exists in both iTregs and naturally occurring Tregs. These findings provide new insights into the immunosuppressive mechanisms of Tregs and suggest a new strategy for improving the therapeutic efficacy of Tregs in established autoimmune disease.

Topics: Adenosine; Animals; Antigens, CD; Apyrase; Autoimmune Diseases; Cyclic AMP; Female; Lymphocyte Activation; Mice; Mice, Inbred C57BL; T-Lymphocytes, Regulatory; Uveitis

Natural regulatory T cells (nTregs) ensure the control of self-tolerance and are currently used in clinical trials to alleviate autoimmune diseases and graft-versus-host disease after hematopoietic stem cell transfer. Based on CD39/CD26 markers, blood nTreg analysis revealed the presence of five different cell subsets, each representing a distinct stage of maturation. Ex vivo added microenvironmental factors, including IL-2, TGFβ, and PGE2, direct the conversion from naive precursor to immature memory and finally from immature to mature memory cells, the latest being a no-return stage. Phenotypic and genetic characteristics of the subsets illustrate the structural parental maturation between subsets, which further correlates with the expression of regulatory factors. Regarding nTreg functional plasticity, both maturation stage and microenvironmental cytokines condition nTreg activities, which include blockade of autoreactive immune cells by cell-cell contact, Th17 and IL-10 Tr1-like activities, or activation of TCR-stimulating dendritic cell tolerization. Importantly, blood nTreg CD39/CD26 profile remained constant over a 2-y period in healthy persons but varied from person to person. Preliminary data on patients with autoimmune diseases or acute myelogenous leukemia illustrate the potential use of the nTreg CD39/CD26 profile as a blood biomarker to monitor chronic inflammatory diseases. Finally, we confirmed that naive conventional CD4 T cells, TCR-stimulated under a tolerogenic conditioned medium, could be ex vivo reprogrammed to FOXP3 lineage Tregs, and further found that these cells were exclusively committed to suppressive function under all microenvironmental contexts.

Topics: Apyrase; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Cellular Microenvironment; Cytokines; Dendritic Cells; Dinoprostone; Dipeptidyl Peptidase 4; Forkhead Transcription Factors; Humans; Interleukin-10; Interleukin-2; Leukemia, Myeloid; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta

Bone destruction is one of many severe complications that occurs in patients with rheumatoid arthritis (RA) and current therapies are unable to cure this manifestation. This study here aims to determine whether GMSC can directly inhibit osteoclast formation and eventually attenuate osteoclastogenesis and bone erosion in an inflammatory milieu.. GMSC were co-cultured with osteoclast precursors with or without CD39 inhibitor, CD73 inhibitor or adenosine receptors inhibitors pretreatment and osteoclast formation were evaluated in vitro. 2×10^6 GMSC per mouse were transferred to CIA mice and pathology scores, the frequency of osteoclasts, bone erosion in joints were assessed in vivo.. GMSC but not control cells, markedly suppressed human or mice osteoclastogenesis in vitro. GMSC treatment also resulted in a dramatically decreased level of NF-κB p65/p50 in osteoclasts in vitro. Infusion of GMSC to CIA significantly attenuated the severity of arthritis, pathology scores, frequency of osteoclasts, particularly bone erosion, as well as a decreased expression of RANKL in synovial tissues in vivo. Blockade of CD39/CD73 or adenosine receptors has significantly abrogated the suppressive ability of GMSC in vitro and therapeutic effect of GMSC on bone erosion during CIA in vivo.. GMSC inhibit osteoclast formation in vitro and in vivo partially via CD39-CD73-adenosine signals. Manipulation of GMSC may have a therapeutic implication on rheumatoid arthritis and other bone erosion related diseases. FUND: This study was supported by grants from the National Key R&D Program of China (2017YFA0105801 to F.H); the Zhujiang Innovative and Entrepreneurial Talent Team Award of Guangdong Province (2016 ZT 06S 252 to F·H) and National Institutes of Health (R01 AR059103, R61 AR073409 and NIH Star Award to S.G.Z).

Topics: Adenosine; Animals; Antigens, CD; Apyrase; Arthritis, Experimental; Arthritis, Rheumatoid; Autoimmune Diseases; Biomarkers; Cell Line; Female; Fibroblasts; Gingiva; Humans; Mesenchymal Stem Cells; Mice; Osteoclasts; Osteogenesis; Signal Transduction; Tomography, X-Ray Computed

TNF inhibitors (TNFi) can induce anti-drug antibodies (ADA) in patients with autoimmune diseases (AID) leading to clinical resistance. We explored a new way of using methotrexate (MTX) to decrease this risk of immunisation.. We treated BAFF transgenic (BAFFtg) mice, a model of AID in which immunisation against biologic drugs is high, with different TNFi. We investigated the effect of a single course of MTX during the first exposure to TNFi. Wild-type (WT) and BAFFtg mice were compared for B-Cell surface markers involved in MTX-related purinergic metabolism, adenosine production and regulatory B-cells (Bregs).We translated the study to macaques and patients with rheumatoid arthritis from the ABIRISK cohort to determine if there was an interaction between serum BAFF levels and MTX that prevented immuniation.. In BAFFtg but not in WT mice or macaques, a single course of MTX prevented immunisation against TNFi and maintained drug concentration for over 52 weeks. BAFFtg mice B-cells expressed more CD73 and CD39 compared to WT mice. MTX induced adenosine release from B cells and increased Bregs and precursors. Use of CD73 blocking antibodies reversed MTX-induced tolerance. In patients from the ABIRISK cohort treated with TNFi for chronic inflammatory diseases, high BAFF serum level correlated with absence of ADA to TNFi only in patients cotreated with MTX but not in patients on TNFi monotherapy.. MTX and BAFF interact in mice where CD73, adenosine and regulatory B cells were identified as key actors in this phenomenon. MTX and BAFF also interact in patients to prevent ADA formation.

Topics: 5'-Nucleotidase; Adenosine; Animals; Antibody Formation; Antigens, CD; Apyrase; Autoimmune Diseases; B-Cell Activating Factor; B-Lymphocytes; Disease Models, Animal; Drug Resistance; Humans; Immunization; Macaca; Methotrexate; Mice; Mice, Transgenic; Tumor Necrosis Factor-alpha

γδ T cells have been shown to have immunoregulatory functions in several experimental autoimmune models. A mutation of the Foxp3 gene leads to the absence of regulatory T cells (Tregs) and a fatal systemic autoimmune disease in scurfy mice. Transfer of scurfy lymphocytes to RAG deficient (RAG(-/-)) recipients reproduces the inflammatory phenotype of the scurfy donor, including hepatitis and pneumonitis. In this study, we show that TCRα(-/-) recipients, which lack αβ T cells but have γδ T cells and B cells, are significantly protected from the hepatitis and pneumonitis, but not the dermatitis, induced by adoptive transfer of scurfy lymphocytes. Cotransfer of γδ T cells, but not B cells, prevented hepatitis and pneumonitis in RAG(-/-) recipients of scurfy lymphocytes. γδ T cells in the TCRα(-/-) recipients of scurfy cells markedly expanded and expressed a highly activated (CD62L(lo)CD44(hi)) phenotype. The activated γδ T cells expressed high levels of CD39 and NKG2D on their cell surface. A high frequency of scurfy T cells in TCRα(-/-) recipients produced IL-10, suggesting that γδ T cells may enhance suppressor cytokine production from scurfy T cells in TCRα(-/-) recipients. This study indicates that γδ T cells may contribute to the maintenance of immunological homeostasis by suppressing autoreactive T cells in liver and lung.

Topics: Adoptive Transfer; Animals; Antigens, CD; Apyrase; Autoimmune Diseases; Autoimmunity; Dermatitis; Forkhead Transcription Factors; Hepatitis; Homeostasis; Interleukin-10; Liver; Lung; Lymphocyte Activation; Mice, Inbred C57BL; NK Cell Lectin-Like Receptor Subfamily K; Pneumonia; Receptors, Antigen, T-Cell, alpha-beta; Receptors, Antigen, T-Cell, gamma-delta; T-Lymphocytes, Regulatory

IL-33 is strongly involved in several inflammatory and autoimmune disorders with both pro- and anti-inflammatory properties. However, its contribution to chronic autoimmune inflammation, such as rheumatoid arthritis, is ill defined and probably requires tight regulation. In this study, we aimed at deciphering the complex role of IL-33 in a model of rheumatoid arthritis, namely, collagen-induced arthritis (CIA). We report that repeated injections of IL-33 during induction (early) and during development (late) of CIA strongly suppressed clinical and histological signs of arthritis. In contrast, a late IL-33 injection had no effect. The cellular mechanism involved in protection was related to an enhanced type 2 immune response, including the expansion of eosinophils, Th2 cells, and type 2 innate lymphoid cells, associated with an increase in type 2 cytokine levels in the serum of IL-33-treated mice. Moreover, our work strongly highlights the interplay between IL-33 and regulatory T cells (Tregs), demonstrated by the dramatic in vivo increase in Treg frequencies after IL-33 treatment of CIA. More importantly, Tregs from IL-33-treated mice displayed enhanced capacities to suppress IFN-γ production by effector T cells, suggesting that IL-33 not only favors Treg proliferation but also enhances their immunosuppressive properties. In concordance with these observations, we found that IL-33 induced the emergence of a CD39(high) Treg population in a ST2L-dependent manner. Our findings reveal a powerful anti-inflammatory mechanism by which IL-33 administration inhibits arthritis development.

Topics: Animals; Antigens, CD; Apyrase; Arthritis, Experimental; Arthritis, Rheumatoid; Autoimmune Diseases; Collagen; Cytokines; Disease Models, Animal; Eosinophils; Interleukin-33; Mice; Mice, Inbred DBA; Spleen; T-Lymphocytes, Regulatory; Th2 Cells

Tolerance established by host-commensal interactions regulates host immunity at both local mucosal and systemic levels. The intestinal commensal strain Bacteroides fragilis elicits immune tolerance, at least in part, via the expression capsular polysaccharide A (PSA). How such niche-specific commensal microbial elements regulate extra-intestinal immune responses, as in the brain, remains largely unknown. We have recently shown that oral treatment with PSA suppresses neuro-inflammation elicited during experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. This protection is dependent upon the expansion of immune-regulatory CD4 T cells (Treg) expressing CD39, an ectonucleotidase. Here, we further show that CD39 modulation of purinergic signals enhances migratory phenotypes of both total CD4 T cells and Foxp3(+) CD4 Tregs at central nervous system (CNS) lymphoid-draining sites in EAE in vivo and promotes their migration in vitro. These changes are noted during PSA treatment, which leads to heightened accumulation of CD39(+) CD4 Tregs in the CNS. Deficiency of CD39 abrogates accumulation of Treg during EAE, and is accompanied by elevated Th1/Th17 signals in the CNS and in gut-associated lymphoid tissues. Our results demonstrate that immune-modulatory commensal bacterial products impact the migratory patterns of CD4 Treg during CNS autoimmunity via the regulation of CD39. These observations provide clues as to how intestinal commensal microbiome is able to modulate Treg functions and impact host immunity in the distal site.

Topics: Animals; Antigens, CD; Apyrase; Autoimmune Diseases; Bacteroides fragilis; CD4-Positive T-Lymphocytes; Disease Models, Animal; Encephalomyelitis; Forkhead Transcription Factors; Immune Tolerance; Mice, Inbred C57BL; Polysaccharides, Bacterial; T-Lymphocytes, Regulatory

The ocular microenvironment uses a poorly defined mela5 receptor (MC5r)-dependent pathway to recover immune tolerance following intraocular inflammation. This dependency is seen in experimental autoimmune uveoretinitis (EAU), a mouse model of endogenous human autoimmune uveitis, with the emergence of autoantigen-specific regulatory immunity in the spleen that protects the mice from recurrence of EAU. In this study, we found that the MC5r-dependent regulatory immunity increased CD11b(+)F4/80(+)Ly-6C(low)Ly-6G(+)CD39(+)CD73(+) APCs in the spleen of post-EAU mice. These MC5r-dependent APCs require adenosine 2A receptor expression on T cells to activate EAU-suppressing CD25(+)CD4(+)Foxp3(+) regulatory T cells. Therefore, in the recovery from autoimmune disease, the ocular microenvironment induces tolerance through a melanocortin-mediated expansion of Ly-6G(+) regulatory APCs in the spleen that use the adenosinergic pathway to promote activation of autoantigen-specific regulatory T cells.

Topics: 5'-Nucleotidase; Animals; Antigens, CD; Antigens, Ly; Apyrase; Autoantigens; Autoimmune Diseases; CD11b Antigen; CD4 Antigens; Disease Models, Animal; Eye; Eye Proteins; Forkhead Transcription Factors; Inflammation; Interleukin-2 Receptor alpha Subunit; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptor, Adenosine A2A; Receptors, Melanocortin; Retinol-Binding Proteins; Self Tolerance; Spleen; T-Lymphocytes, Regulatory; Uveitis

The ectonucleotidase CD39 has recently been described as being highly expressed on regulatory Foxp3(+) CD4 T cells. Through hydrolysis of proinflammatory extracellular ATP, CD39 activity represents a newly described mechanism of regulatory T cell action. We report a novel population of human CD4 T cells that express CD39 yet are Foxp3 negative. These cells produce the proinflammatory cytokines IFN-gamma and IL-17 and fail to suppress proliferation; however, they still have high ATP hydrolysis activity. In the inflammatory site in human juvenile idiopathic arthritis, the CD39(+)Foxp3(-) population is greatly increased compared with peripheral blood of patients or healthy controls. We also show that cells expressing the AMPase CD73 are less frequent in the joint than in blood. To our knowledge, this is the first study to describe and characterize CD39 function on CD4 T cells from the target site in a human autoinflammatory condition. Our data suggest that in human CD4(+) T cells from the inflamed site, CD39 can be highly expressed on two populations, one regulatory and the other of a memory phenotype.

Topics: Adolescent; Antigens, CD; Apyrase; Arthritis, Juvenile; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Child; Female; Gene Expression Regulation, Enzymologic; Humans; Immunologic Memory; Immunophenotyping; Inflammation; Inflammation Mediators; Male; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory