Foxp3+CD39+CD73+ regulatory T-cells are decreased in the peripheral blood of women with deep infiltrating endometriosis.

Endometriosis's pathophysiology remains incompletely understood, with evidence pointing towards a dysregulated immune response. Regulatory T (Treg) cells, pivotal in maintaining self-tolerance, may facilitate the survival of ectopic endometrial cells within the abdominal cavity, thereby contributing to endometriosis development. This study aimed to assess the prevalence of CD39+CD73+ suppressor Treg cell subsets in the peripheral blood of endometriosis patients. This research focuses on the pivotal role of regulatory T-cells (Tregs), which are essential for maintaining immune tolerance and preventing autoimmune diseases. A case-control study was conducted, including 32 women diagnosed with endometriosis and 22 control subjects. The frequency of peripheral blood CD39+CD73+ suppressor Treg cells was quantified using flow cytometry. No significant differences were observed in the frequency of CD3+CD4+CD25High cells (Median [M]: 10.1; Interquartile Range [IQR]: 6.32‒18.3 vs. M: 9.72; IQR: 6.22-19.8) or CD3+CD4+CD25HighCD39+Foxp3+ cells (M: 31.1; IQR: 19.7-44.0 vs. M: 30.55; IQR: 18.5-45.5) between controls and patients. However, a significantly lower frequency of CD3+CD4+CD25HighCD39+CD73+ cells was observed in the endometriosis group compared to controls (M: 1.98; IQR: 0.0377-3.17 vs. M: 2.25; IQR: 0.50-4.08; p = 0.0483), suggesting a reduction in systemic immune tolerance among these patients. This finding highlights the potential role of CD39 and CD73 expression on Treg cells as biomarkers for assessing disease severity and progression. Furthermore, elucidating the mechanisms driving these alterations may unveil new therapeutic strategies to restore immune equilibrium and mitigate endometriosis symptoms.

Bone-derived MSCs encapsulated in alginate hydrogel prevent collagen-induced arthritis in mice through the activation of adenosine A2A/2B receptors in tolerogenic dendritic cells.

Tolerogenic dendritic cells (tolDCs) facilitate the suppression of autoimmune responses by differentiating regulatory T cells (Treg). The dysfunction of immunotolerance results in the development of autoimmune diseases, such as rheumatoid arthritis (RA). As multipotent progenitor cells, mesenchymal stem cells (MSCs), can regulate dendritic cells (DCs) to restore their immunosuppressive function and prevent disease development. However, the underlying mechanisms of MSCs in regulating DCs still need to be better defined. Simultaneously, the delivery system for MSCs also influences their function. Herein, MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ, maximizing efficacy in vivo. The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines. In the collagen-induced arthritis (CIA) mice model, alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39+CD73+ on MSCs. These enzymes hydrolyze ATP to adenosine and activate A2A/2B receptors on immature DCs, further promoting the phenotypic transformation of DCs to tolDCs and regulating naïve T cells to Tregs. Therefore, encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression. This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.

Aspirin ameliorates atherosclerotic immuno-inflammation through regulating the Treg/Th17 axis and CD39-CD73 adenosine signaling via remodeling the gut microbiota in ApoE-/- mice.

The gut microbiome has been implicated in the development of cardiovascular disease (CVD) and atherosclerosis (AS), a chronic inflammatory condition. Aspirin may improve the immuno-inflammatory status in AS by regulating microbiota dysbiosis. However, the potential role of aspirin in modulating gut microbiota and microbial-derived metabolites remains less explored. In this study, we investigated the effect of aspirin treatment on AS progression by modulating gut microbiota and microbial-derived metabolites in apolipoprotein E-deficient (ApoE-/-) mice. We analyzed the fecal bacterial microbiome and targeted metabolites, including short-chain fatty acids (SCFAs) and bile acids (BAs). The immuno-inflammatory status of AS was evaluated by analyzing regulatory T cells (Tregs), Th17 cells, and the CD39-CD73 adenosine signaling pathway involved in purinergic signaling. Our results indicated that aspirin altered gut microbiota, leading to an increase in the phylum Bacteroidetes and a decrease in the Firmicutes to Bacteriodetes (F/B) ratio. Aspirin treatment also increased levels of targeted SCFA metabolites, such as propionic acid, valeric acid, isovaleric acid, and isobutyric acid. Furthermore, aspirin impacted BAs by reducing the level of harmful deoxycholic acid (DCA) and increasing the levels of beneficial isoalloLCA and isoLCA. These changes were accompanied by a rebalancing of the ratio of Tregs to Th17 cells and an increase in the expression of ectonucleotidases CD39 and CD73, thereby ameliorating inflammation. These findings suggest that aspirin has an athero-protective effect with an improved immuno-inflammatory profile, partially attributed to its manipulation of the gut microbiota.

CD73/NT5E-mediated ubiquitination of AURKA regulates alcohol-related liver fibrosis via modulating hepatic stellate cell senescence.

Alcohol-related liver disease (ALD) is the most common chronic liver disease worldwide; however, no effective treatment to prevent the progression of alcohol-related liver fibrosis (ALF) is available. CD73/NT5E, a nucleotidase, controls cellular homeostasis by combining extracellular purinergic signaling with intracellular kinase activity and gene transcription and is associated with cell proliferation, differentiation, and death. In this study, we demonstrated that CD73/NT5E had a more significant regulatory effect on the activation, proliferation, and apoptosis of HSCs compared with that of CD39/ENTPD1. We examined the expression of CD73/NT5E in the normal and fibrotic human livers. The absence of CD73/NT5E was protective in mouse models of ALF. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that CD73/NT5E overexpression was related to the p53 signaling pathway, which regulates cell senescence. Proteins interacting with p53 were predicted using the STRING database. The overlap between proteomic analysis and STRING databases was for Aurora kinase A (AURKA), a cell cycle-regulated kinase. Coimmunoprecipitation (co-IP) assay and molecular docking confirmed that CD73/NT5E directly interacted with AURKA. We found that overexpression of CD73/NT5E inhibited AURKA ubiquitination, whereas p53 signaling was downregulated. Mechanistically, CD73/NT5E regulated ALF and the activation and senescence of stellate cells by binding to AURKA. These findings indicate that CD73/NT5E is a potential therapeutic target for ALF.

Bone-derived MSCs encapsulated in alginate hydrogel prevent collagen-induced arthritis in mice through the activation of adenosine A2A/2B receptors in tolerogenic dendritic cells

Tolerogenic dendritic cells (tolDCs) facilitate the suppression of autoimmune responses by differentiating regulatory T cells (Treg). The dysfunction of immunotolerance results in the development of autoimmune diseases, such as rheumatoid arthritis (RA). As multipotent progenitor cells, mesenchymal stem cells (MSCs), can regulate dendritic cells (DCs) to restore their immunosuppressive function and prevent disease development. However, the underlying mechanisms of MSCs in regulating DCs still need to be better defined. Simultaneously, the delivery system for MSCs also influences their function. Herein, MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ, maximizing efficacy in vivo. The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines. In the collagen-induced arthritis (CIA) mice model, alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39+CD73+ on MSCs. These enzymes hydrolyze ATP to adenosine and activate A2A/2B receptors on immature DCs, further promoting the phenotypic transformation of DCs to tolDCs and regulating naïve T cells to Tregs. Therefore, encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression. This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.

Istradefylline modulates purinergic enzymes and reduces malignancy-associated factors in B16F10 melanoma cells.

ATP and adenosine exert pivotal roles in the development, maintenance, and metastatic spreading of melanoma. The action of such key melanoma tumor microenvironment (TME) constituents might be complementary or opposed, and their effects are not exclusive to immune cells but also to other host cells and tumor cells. The effects of ATP are controlled by the axis CD39/73, resulting in adenosine, the main actor in the TME, and A2A is the crucial mediator of its effects. We evaluated ATP and adenosine signaling through A2A on B16F10 melanoma cells using istradefylline (IST) (antiparkinsonian A2A antagonist) and caffeine (CAF) treatments after exposure to ATP and adenosine. Adenosine increased melanoma cell viability and proliferation in a concentration-dependent manner. ATP increases viability only as a substrate by CD39 to produce adenosine. Both IST and CAF are toxic to B16F10 cells, but only IST potentialized paclitaxel-induced cytotoxic effects, even decreasing its IC50 value. IST positively modulated CD39 and CD73 expression. CD39 activity was increased, and E-ADA was reduced, indicating that the melanoma cells promoted compensatory feedback in the production and maintenance of adenosine levels. A2A antagonism by IST reduced the factors associated with malignancy, like migration, adhesion, colony formation, and the capacity to produce melanin. Moreover, IST significantly increases nitric oxide (NO) production, which correlates to a decline in melanoma cell viability by apoptotic events. Altogether, our results suggest that adenosine signaling through A2A is essential for B16F10 cells, and its inhibition by IST causes compensatory purinergic enzymatic modulations. Furthermore, IST is a promising therapy that provides new ways to improve current melanoma treatments.

Dynamic Adjust of Non-Radiative and Radiative Attenuation of AIE Molecules Reinforces NIR-II Imaging Mediated Photothermal Therapy and Immunotherapy.

Due to the aggregation-caused quenching effect and near-infrared I poor penetration capabilities of common fluorescent molecules, their applications in visualized imaging and photoactivated treatment are limited. Therefore, new near-infrared II (NIR-II) molecule (named TST), which had the abilities of aggregation-induced emission (AIE) and photothermal therapy are synthesized. Moreover, in order to further improve its fluorescent yield and therapeutic effect, camptothecin prodrug (CPT-S-PEG) and novel immune checkpoint inhibitor AZD4635 are used to co-assemble with TST into nanoparticles for drug delivery. On account of the strong interaction of camptothecin and TST, the intramolecular rotation of TST is limited, thereby inhibiting non-radiation attenuation and promoting fluorescence generation when the nanoparticles are intact. As nanoparticles uptake by cancer cells, redox sensitive CPT-S-PEG is degraded and the nanoparticles disintegrate. The released TST enhances non-radiative attenuation and expedites photothermal conversion because of the removal of the constraint of camptothecin. Furthermore, photothermal therapy induces immunogenic cell death of cancer cells and releases abundant ATP into the tumor microenvironment to recruit immune cells. However, superfluous ATP is converted into immunosuppressive adenosine through the CD39-CD73-A2AR pathway. The AZD4635 released by photothermal disintegration of the nanoparticles just blocks this pathway timely, achieving favorable synergistic effect of photothermal therapy, chemotherapy, and immunotherapy.

Susceptibility of aging mice to listeriosis: Role of anti-inflammatory responses with enhanced Treg-cell expression of CD39/CD73 and Th-17 cells.

Foodborne Listeria monocytogenes (Lm) causes serious illness and death in immunosuppressed hosts, including the elderly population. We investigated Lm susceptibility and inflammatory cytokines in geriatric mice. Young-adult and old mice were gavaged with a Lm strain Lmo-InlAm. Tissues were assayed for Lm burden and splenocytes were analyzed for Th1/Th2/Th17/Treg responses and expression of CD39 and CD73. Old Lm-infected mice lost body-weight dose-dependently, had higher Lm colonization, and showed higher inflammatory responses than Lm-infected young-adult mice. After infection, IL-17 levels increased significantly in old mice whereas IFN-γ levels were unchanged. Levels of IL-10 and Treg cells were increased in infected old mice as compared to infected young-adult mice. Age-dependent enhanced expression of CD39/CD73 was observed in purified Treg prior to infection, suggesting increased baseline adenosine production in old mice. Lm lysate-treated splenocytes from older mice produced significantly higher levels of IL-10, IL17, and IL-1ß, produced less IFN-γ and IL-2, and proliferated less than splenocytes from young-adult mice. Data suggests that older mice maybe more susceptible to Lm infection due to an imbalance of Th cell responses with disproportionate and persistent anti-inflammatory responses. Lm infection enhanced differentiation of proinflammatory Th17 cells, which may also exacerbate pathological responses during listeriosis.

Unfolding Role of a Danger Molecule Adenosine Signaling in Modulation of Microbial Infection and Host Cell Response.

Ectonucleotidases CD39 and CD73, specific nucleotide metabolizing enzymes located on the surface of the host, can convert a pro-inflammatory environment driven by a danger molecule extracellular-ATP to an adenosine-mediated anti-inflammatory milieu. Accordingly, CD39/CD73 signaling have has strongly implicated in modulating the intensity, duration, and composition of purinergic danger signals delivered to host. Recent studies have eluted potential roles for CD39 and CD73 in selective triggering of a variety of host immune cells and molecules in the presence of pathogenic microorganisms or microbial virulence molecules. Growing evidence also suggests that CD39 and CD73 present complimentary, but likely differential, actions against pathogens to shape the course and severity of microbial infection as well as the associated immune response. Similarly, adenosine receptors A2A and A2B have been proposed to be major immunomodulators of adenosine signaling during chronic inflammatory conditions induced by opportunistic pathogens, such as oral colonizer Porphyromonas gingivalis. Therefore, we here review the recent studies that demonstrate how complex network of molecules in the extracellular adenosine signaling machinery and their interactions can reshape immune responses and may also be targeted by opportunistic pathogens to establish successful colonization in human mucosal tissues and modulate the host immune response.

Mesenchymal stromal cells derived from cervical cancer produce high amounts of adenosine to suppress cytotoxic T lymphocyte functions.

BACKGROUND: In recent years, immunomodulatory mechanisms of mesenchymal stem/stromal cells (MSCs) from bone marrow and other "classic" sources have been described. However, the phenotypic and functional properties of tumor MSCs are poorly understood. The aim of this study was to analyze the immunosuppressive capacity of cervical cancer-derived MSCs (CeCa-MSCs) on effector T lymphocytes through the purinergic pathway. METHODS: We determined the expression and functional activity of the membrane-associated ectonucleotidases CD39 and CD73 on CeCa-MSCs and normal cervical tissue-derived MSCs (NCx-MSCs). We also analyzed their immunosuppressive capacity to decrease proliferation, activation and effector cytotoxic T (CD8+) lymphocyte function through the generation of adenosine (Ado). RESULTS: We detected that CeCa-MSCs express higher levels of CD39 and CD73 ectonucleotidases in cell membranes compared to NCx-MSCs, and that this feature was associated with the ability to strongly suppress the proliferation, activation and effector functions of cytotoxic T-cells through the generation of large amounts of Ado from the hydrolysis of ATP, ADP and AMP nucleotides. CONCLUSIONS: This study suggests that CeCa-MSCs play an important role in the suppression of the anti-tumor immune response in CeCa through the purinergic pathway.

CD73-adenosine reduces immune responses and survival in ovarian cancer patients.

Multiple non-redundant immunosuppressive pathways are active within the microenvironment of cancers to avoid tumor eradication by the immune system. Our results demonstrate that the CD73-adenosine pathway is a major immunosuppressive mechanism co-opted by ovarian tumors to escape antitumor immunity. In ovarian cancer patients, high CD73 expression correlates with poor outcome and impaired CD8(+) T cell immunosurveillance.

Inflammatory Disequilibrium in Stroke.

Over the past several decades, there have been substantial advances in our knowledge of the pathophysiology of stroke. Understanding the benefits of timely reperfusion has led to the development of thrombolytic therapy as the cornerstone of current management of ischemic stroke, but there remains much to be learned about mechanisms of neuronal ischemic and reperfusion injury and associated inflammation. For ischemic stroke, novel therapeutic targets have continued to remain elusive. When considering modern molecular biological techniques, advanced translational stroke models, and clinical studies, a consistent pattern emerges, implicating perturbation of the immune equilibrium by stroke in both central nervous system injury and repair responses. Stroke triggers activation of the neuroimmune axis, comprised of multiple cellular constituents of the immune system resident within the parenchyma of the brain, leptomeninges, and vascular beds, as well as through secretion of biological response modifiers and recruitment of immune effector cells. This neuroimmune activation can directly impact the initiation, propagation, and resolution phases of ischemic brain injury. To leverage a potential opportunity to modulate local and systemic immune responses to favorably affect the stroke disease curve, it is necessary to expand our mechanistic understanding of the neuroimmune axis in ischemic stroke. This review explores the frontiers of current knowledge of innate and adaptive immune responses in the brain and how these responses together shape the course of ischemic stroke.

Synergy between the ectoenzymes CD39 and CD73 contributes to adenosinergic immunosuppression in human malignant gliomas.

BACKGROUND: The importance of ectoenzymes CD39 and CD73 in mediating adenosinergic immunosuppression has been recognized, but their roles in human malignant glioma-associated immunosuppression remain largely unknown. METHODS: In this study, the ectoenzyme characteristics of malignant glioma cells and infiltrating CD4(+) T lymphocytes isolated from newly diagnosed malignant glioma patients were investigated. The ectoenzyme activities of both cell populations were determined by nucleotide hydrolysis assay. The immunosuppressive property of the CD39-CD73 synergic effect was evaluated via responder T-cell proliferation assay. RESULTS: We observed that CD39(-)CD73(+) glioma cells and infiltrating CD4(+)CD39(high)CD73(low) T lymphocytes exhibited 2 distinct but complementary ectoenzyme phenotypes, which were further verified by enzyme activity assay. The nucleotide hydrolysis cascade was incomplete unless CD39 derived from T lymphocytes and CD73 collaborated synergistically. We demonstrated that increased suppression of responder CD4(+) T-cell proliferation suppression was induced by CD4(+)CD39(+) T cells in the presence of CD73(+) glioma cells, which could be alleviated by the CD39 inhibitor ARL67156, the CD73 inhibitor APCP, or the adenosine receptor A2aR antagonist SCH58261. In addition, survival analysis suggested that CD73 downregulation was a positive prognostic factor related to the extended disease-free survival of glioblastoma patients. CONCLUSIONS: Our data indicate that glioma-derived CD73 contributes to local adenosine-mediated immunosuppression in synergy with CD39 from infiltrating CD4(+)CD39(+) T lymphocytes, which could become a potential therapeutic target for treatment of malignant glioma and other immunosuppressive diseases.