apyrase and Multiple-Sclerosis

Multiple sclerosis (MS) is a highly disabling, progressive neurodegenerative disease with no curative treatment available. Although significant progress has been made in understanding how MS develops, there remain aspects of disease pathogenesis that are yet to be fully elucidated. In this regard, studies have shown that dysfunctional adenosinergic signaling plays a pivotal role, as patients with MS have altered levels adenosine (ADO), adenosine receptors and proteins involved in the generation and termination of ADO signaling, such as CD39 and adenosine deaminase (ADA). We have therefore performed a literature review regarding the involvement of the adenosinergic system in the development of MS and propose mechanisms by which the modulation of this system can support drug development and repurposing.

Topics: Adenosine; Adenosine Deaminase; Apyrase; Humans; Multiple Sclerosis; Neurodegenerative Diseases; Receptors, Purinergic P1; Signal Transduction

Mood disorders have been associated with risk of clinical relapses in multiple sclerosis (MS), a demyelinating disease mediated by myelin-specific T cells.. We aimed to investigate the impact of major depressive disorder (MDD) and cytokine profile of T-cells in relapsing remitting MS patients.. For our study, plasma and PBMC were obtained from 60 MS patients (30 with lifetime MDD) in remission phase. The PBMC cultures were stimulated with anti-CD3/anti-CD28 beads or myelin basic protein (MBP), and effector and regulatory T cell phenotypes were determined by flow cytometry. The cytokine levels, both in the plasma or in the supernatants collected from PBMC cultures, were quantified by Luminex. In some experiments, the effect of serotonin (5-HT) was investigated.. In summary, our findings suggested that recurrent major depression, by favoring imbalances of effector Th17 and Treg cell subsets, contributes to MS severity.

Topics: Apyrase; Autoantigens; CD8-Positive T-Lymphocytes; Cytokines; Depressive Disorder, Major; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Interleukin-17; Leukocytes, Mononuclear; Multiple Sclerosis; Myelin Sheath; Serotonin; T-Lymphocytes, Regulatory; Th17 Cells

In multiple sclerosis (MS), Th17 cells are critical drivers of autoimmune central nervous system (CNS) inflammation and demyelination. Th17 cells exhibit functional heterogeneity fostering both pathogenic and nonpathogenic, tissue-protective functions. Still, the factors that control Th17 pathogenicity remain incompletely defined. Here, using experimental autoimmune encephalomyelitis, an established mouse MS model, we report that therapeutic administration of activin-A ameliorates disease severity and alleviates CNS immunopathology and demyelination, associated with decreased activation of Th17 cells. In fact, activin-A signaling through activin-like kinase-4 receptor represses pathogenic transcriptional programs in Th17-polarized cells, while it enhances antiinflammatory gene modules. Whole-genome profiling and in vivo functional studies revealed that activation of the ATP-depleting CD39 and CD73 ectonucleotidases is essential for activin-A-induced suppression of the pathogenic signature and the encephalitogenic functions of Th17 cells. Mechanistically, the aryl hydrocarbon receptor, along with STAT3 and c-Maf, are recruited to promoter elements on

Topics: 5'-Nucleotidase; Activins; Animals; Antigens, CD; Apyrase; Cell Differentiation; Encephalomyelitis, Autoimmune, Experimental; GPI-Linked Proteins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Th17 Cells

Regulatory T Cells (Tregs) are a T-lymphocyte subset involved in the maintenance of immune peripheral tolerance. Despite evidence of the adaptive immune system's role in Alzheimer's Disease (AD), the involvement of Tregs is still not clear. We focused on the Flow-Cytometry analysis of the Treg frequencies and phenotypes in the AD. The aim of the study is to analyse similarities and differences in Tregs profile between Alzheimer's Disease and Multiple Sclerosis. Regulatory T Cells (CD4+/CD25high/CD127low-neg) were identified using an innovative Flow Cytometry method and subtyped as Resting (analysed CD45RApos/CD25dim), Activated (CD45RAneg/CD25bright) and Secreting (CD45RAneg/CD25dim) cells. Our data demonstrate a significant decrease in the total and Resting Tregs in AD patients when compared to healthy subjects. The percentage of the results of the Resting Tregs were also reduced in MS patients together with a parallel frequency increase of Activated Tregs. Our data suggest that altered Treg phenotypes observed in both diseases could play a role in the impairment of the Treg-mediated immunological tolerance, recalling a possible link between the two pathologies. Given that this study was conducted on a restricted population, if confirmed by a further and enlarged study, the implications of the autoimmune mechanisms in AD pathophysiology could open new immunotherapeutic perspectives based on Treg modulation.

Topics: Adult; Aged; Alzheimer Disease; Antigens, CD; Apyrase; Female; HLA-DR Antigens; Humans; Male; Middle Aged; Multiple Sclerosis; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Up-Regulation

While examining the therapeutic value of anti-CD52 antibody against EAE/MS, we identified a unique subset of CD39+ Tregs in repopulating GALT tissues, a major lymphoid reservoir, which was accompanied by amelioration of disease. Furthermore, anti-CD52 treatment leads to increased expression of BDNF, IL-10, and SMAD3 in the brains of EAE mice. This condition is associated with suppression of IL-17, a critical inflammatory factor in EAE/MS progression. Additionally, we found elevated levels of CD4+CD39+ Tregs in PBMCs of RRMS patients treated with humanized anti-CD52 mAb. Thus, anti-CD52 can affect multiple immune mediated pathways involved in the pathogenesis of EAE/MS.

Topics: Animals; Antibodies, Monoclonal; Antigens, CD; Antigens, Neoplasm; Apyrase; CD4-Positive T-Lymphocytes; CD52 Antigen; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Forkhead Transcription Factors; Glycoproteins; Humans; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Treatment Outcome

The mammalian immune system constitutively senses vast quantities of commensal bacteria and their products through pattern recognition receptors, yet excessive immune reactivity is prevented under homeostasis. The intestinal microbiome can influence host susceptibility to extra-intestinal autoimmune disorders. Here we report that polysaccharide A (PSA), a symbiosis factor for the human intestinal commensal Bacteroides fragilis, protects against central nervous system demyelination and inflammation during experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, through Toll-like receptor 2 (TLR2). TLR2 mediates tissue-specific expansion of a critical regulatory CD39(+) CD4 T-cell subset by PSA. Ablation of CD39 signalling abrogates PSA control of EAE manifestations and inflammatory cytokine responses. Further, CD39 confers immune-regulatory phenotypes to total CD4 T cells and Foxp3(+) CD4 Tregs. Importantly, CD39-deficient CD4 T cells show an enhanced capability to drive EAE progression. Our results demonstrate the therapeutic potential and underlying mechanism by which an intestinal symbiont product modulates CNS-targeted demyelination.

Topics: Animals; Antigens, CD; Apyrase; Bacteroides fragilis; CD4-Positive T-Lymphocytes; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Forkhead Transcription Factors; Humans; Inflammation; Intestinal Mucosa; Intestines; Mice, Inbred C57BL; Mice, Knockout; Multiple Sclerosis; Polysaccharides, Bacterial; Signal Transduction; Symbiosis; Toll-Like Receptor 2

Multiple sclerosis (MS) likely results from an imbalance between regulatory and inflammatory immune processes. CD39 is an ectoenzyme that cleaves ATP to AMP and has been suggested as a novel regulatory T cells (Treg) marker. As ATP has numerous proinflammatory effects, its degradation by CD39 has anti-inflammatory influence. The purpose of this study was to explore regulatory and inflammatory mechanisms activated in fingolimod treated MS patients.. Peripheral blood mononuclear cells (PBMCs) were isolated from relapsing-remitting MS patients before starting fingolimod and three months after therapy start. mRNA expression was assessed in ex vivo PBMCs. The proportions of CD8, B cells, CD4 and CD39-expressing cells were analysed by flow cytometry. Treg proportion was quantified by flow cytometry and methylation-specific qPCR. Fingolimod treatment increased mRNA levels of CD39, AHR and CYP1B1 but decreased mRNA expression of IL-17, IL-22 and FOXP3 mRNA in PBMCs. B cells, CD4+ cells and Treg proportions were significantly reduced by this treatment, but remaining CD4+ T cells were enriched in FOXP3+ cells and in CD39-expressing Tregs.. In addition to the decrease in circulating CD4+ T cells and CD19+ B cells, our findings highlight additional immunoregulatory mechanisms induced by fingolimod.

Topics: Antigens, CD; Antigens, CD19; Apyrase; B-Lymphocytes; Basic Helix-Loop-Helix Transcription Factors; CD4-Positive T-Lymphocytes; Cytochrome P-450 CYP1B1; Cytokines; Fingolimod Hydrochloride; Gene Expression Regulation; Humans; Immunosuppressive Agents; Multiple Sclerosis; Receptors, Aryl Hydrocarbon; T-Lymphocytes, Regulatory

Multiple sclerosis (MS) is a demyelinating neurological disease, which is presumed to be a consequence of infiltrating lymphocytes that are autoreactive to myelin proteins. ATP and adenosine contribute to fine-tuning immune responses and NTPDase (CD39) and adenosine deaminase (ADA) are important enzymes in the control of the extracellular levels of these molecules at the site of inflammation. We evaluated the activity and expression of NTPDase and adenosine deaminase (ADA) activity in lymphocytes from patients with the relapsing-remitting form of MS (RRMS).. This study involved 22 patients with RRMS and 22 healthy subjects as a control group. The lymphocytes were isolated from blood and separated on Ficoll density gradients and after isolation the NTPDase and ADA activities were determined.. The NTPDase activity and expression were increased in lymphocytes from RRMS patients when compared with the control group (p<0.05). In addition, a decrease in ADA activity was observed in lymphocytes from these patients when compared to the control group (p<0.05).. The regulation of ATP and adenosine levels by NTPDase and ADA activities may be important to preserve cellular integrity and to modulate the immune response in MS.

Topics: Adenosine Deaminase; Adenosine Diphosphate; Adenosine Triphosphate; Adult; Aged; Antigens, CD; Apyrase; Case-Control Studies; Female; Gene Expression Regulation, Enzymologic; Humans; Lymphocytes; Male; Middle Aged; Multiple Sclerosis; Recurrence

The aim of the present study was to analyze the activities of extracellular purine metabolizing enzymes, CD39 (apyrase, EC 3.6.1.5) and CD73 (ecto-5' nucleotidase, EC 3.1.3.5) in experimental autoimmune encephalomyelitis (EAE). The levels of ATP, ADP and AMP hydrolysis were analyzed in the blood serum and in the rat spinal cord plasma membrane preparation 8, 15 and 25 days after induction of EAE. The animals were divided in three groups: control (saline), CFA (adjuvant-only) and EAE (CFA and homogenate of spinal cords). Eight days after immunization, ATP, ADP and AMP hydrolysis in the blood serum and spinal cord membrane preparations were unaffected in EAE compared to both, control and CFA group. In the peak of disease, ATP, ADP and AMP hydrolysis in EAE group showed significant decrease in the blood serum and prominent increase in the spinal cord membrane preparation compared to CFA and control group. At the end of illness, as judged by disappearance of clinical manifestation of EAE, ATP, ADP and AMP hydrolysis, although closer to CFA levels, were still significantly different in respect to the CFA group. Modulation of ATP, ADP and AMP hydrolysis suggests that they operate during EAE and might represent the basis of novel therapeutic strategies in immune-mediated diseases, such as MS.

Topics: 5'-Nucleotidase; Adenosine; Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Animals; Apyrase; Cell Membrane; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Multiple Sclerosis; Rats; Rats, Inbred Strains; Spinal Cord; Time Factors

Despite the fact that CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg cells) play a central role in maintaining self-tolerance and that IL-17-producing CD4(+) T cells (Th17 cells) are pathogenic in many autoimmune diseases, evidence to date has indicated that Th17 cells are resistant to suppression by human Foxp3(+) Treg cells. It was recently demonstrated that CD39, an ectonucleotidase which hydrolyzes ATP, is expressed on a subset of human natural Treg cells. We found that although both CD4(+)CD25(high)CD39(+) and CD4(+)CD25(high)CD39(-) T cells suppressed proliferation and IFN-gamma production by responder T cells, only the CD4(+)CD25(high)CD39(+), which were predominantly FoxP3(+), suppressed IL-17 production, whereas CD4(+)CD25(high)CD39(-) T cells produced IL-17. An examination of T cells from multiple sclerosis patients revealed a normal frequency of CD4(+)CD25(+)CD127(low)FoxP3(+), but interestingly a deficit in the relative frequency and the suppressive function of CD4(+)CD25(+)CD127(low)FoxP3(+)CD39(+) Treg cells. The mechanism of suppression by CD39(+) Treg cells appears to require cell contact and can be duplicated by adenosine, which is produced from ATP by the ectonucleotidases CD39 and CD73. Our findings suggest that CD4(+)CD25(+)Foxp3(+)CD39(+) Treg cells play an important role in constraining pathogenic Th17 cells and their reduction in multiple sclerosis patients might lead to an inability to control IL-17 mediated autoimmune inflammation.

Topics: Adenosine; Adult; Antigens, CD; Apyrase; Cell Communication; Female; Flow Cytometry; Forkhead Transcription Factors; Humans; Interleukin-17; Male; Multiple Sclerosis; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory

One of the characteristics of ongoing demyelination in multiple sclerosis (MS) is the accumulation of lipid-laden macrophages in active lesions. Little is known about the source of these macrophages in the early stages of plaque evolution as microglial-derived and haematogenous macrophages share morphological characteristics and most cell surface antigens. A key issue in understanding the pathogenesis of MS is the reliable identification of phagocytes capable of degrading myelin and presenting autoantigen to T cells at the onset of demyelination. Using a combination of histochemistry and immunocytochemistry, an average of 60% of EBM11+ phagocytes (EMBII is a pan-macrophage marker) in early active MS plaques, defined as lesions with myelin-containing phagocytes but no obvious parenchymal myelin loss around these cells, were judged to originate from microglia as they exhibited nucleoside diphosphatase activity, a microglial marker. Only 4-15% of EBM11+ phagocytes in these lesions exhibited non-specific esterase activity, an enzyme marker for monocytes and macrophages. In contrast, 30-80% of EBM11+ phagocytes in more advanced active plaques with partial or complete myelin loss in the parenchyma were non-specific esterase+. Lysosomal enzyme acid phosphatase activity was strongly exhibited by 90% of phagocytes in all active plaques and there was a significant correlation between numbers of acid phosphatase+ cells and oil red O+ foamy macrophages. The results indicate that microglia are the main population of phagocytes in the early stages of demyelination and may play an important role in the pathogenesis of MS.

Topics: Acid Phosphatase; Adult; Aged; Apyrase; Brain; Humans; Immunohistochemistry; Lipid Metabolism; Lysosomes; Macrophages; Microglia; Middle Aged; Multiple Sclerosis; Spinal Cord