Regulation of Treg-associated CD39 in multiple sclerosis and effects of corticotherapy during relapse. Muls Nathalie G V,Dang Hong Anh,Sindic Christian J M,van Pesch Vincent Multiple sclerosis (Houndmills, Basingstoke, England) BACKGROUND:Accumulating data highlight proinflammatory processes leading to MS relapses. Whether anti-inflammatory mechanisms are concomitantly activated is unclear. The ectonucleotidase CD39 has been described as a novel T regulatory cell (Treg) marker. The purpose of this study was to explore whether regulatory mechanisms are activated during MS relapses and reinforced by intravenous methylprednisolone (ivMP). METHODS:Blood samples were collected from stable and relapsing MS patients and healthy controls. We used FOXP3 methylation-specific qPCR and CD4(+)CD25(high)FOXP3(+) analysis to quantify Tregs. Cytokine mRNA expression levels were measured in peripheral blood mononuclear cells (PBMCs) and in CD4(+) T cells. CD39 expression was determined by flow cytometry in monocytes, NK, T and B cells. CD39 enzymatic activity was assessed by ATP luminometry. RESULTS:The proportion of Tregs was similar in relapsing MS patients and healthy controls. CD39 mRNA level was higher in PBMCs of relapsing MS patients than in controls. The proportion of CD39-expressing Tregs was higher in MS patients. IvMP decreased the overall proportion of Tregs while it increased CD39 mRNA levels, the proportions of CD39-expressing Tregs and monocytes as well as CD39 ectonucleotidase activity. CONCLUSIONS:Our data suggest that immunoregulatory mechanisms are ongoing in MS patients, particularly during relapses, and strengthened by ivMP. 10.1177/1352458514567215
    Targeting CD39 in cancer. Moesta Achim K,Li Xian-Yang,Smyth Mark J Nature reviews. Immunology The ATP-adenosine pathway functions as a key modulator of innate and adaptive immunity within the tumour microenvironment. Consequently, multiple clinical strategies are being explored to target this pathway for the treatment of cancer; in particular, recent clinical data with CD73 antagonists and inhibitors of A receptors have demonstrated the therapeutic potential of modulating this pathway. Now, inhibitors of the ectonucleotidase CD39, the rate-limiting enzyme in the conversion of ATP to immunomodulatory adenosine, are entering clinical trials. Consequently, there is currently a focus on understanding the impact of CD39 enzymatic function on innate and adaptive immunity and how therapeutic modulation of this pathway alters their functional potential within the tumour microenvironment. Recent findings reveal multipronged mechanisms of action of CD39 antagonism that rely not only on preventing the accumulation of adenosine but also on the stabilization of pro-inflammatory extracellular ATP to restore antitumour immunity. Here, we review the impact of CD39 expression and ectonucleotidase activity on immunity with a focus on the setting of oncology. Additionally, we discuss the implications for immunotherapy strategies targeting CD39, including their inclusion in rational combination therapies. 10.1038/s41577-020-0376-4
    Ecto-NTPDase CD39 is a negative checkpoint that inhibits follicular helper cell generation. Cao Wenqiang,Fang Fengqin,Gould Timothy,Li Xuanying,Kim Chulwoo,Gustafson Claire,Lambert Simon,Weyand Cornelia M,Goronzy Jörg J The Journal of clinical investigation Vaccination is a mainstay in preventive medicine, reducing morbidity and mortality from infection, largely by generating pathogen-specific neutralizing antibodies. However, standard immunization strategies are insufficient with increasing age due to immunological impediments, including defects in T follicular helper (Tfh) cells. Here, we found that Tfh generation is inversely linked to the expression of the ecto-NTPDase CD39 that modifies purinergic signaling. The lineage-determining transcription factor BCL6 inhibited CD39 expression, while increased Tfh frequencies were found in individuals with a germline polymorphism preventing transcription of ENTPD1, encoding CD39. In in vitro human and in vivo mouse studies, Tfh generation and germinal center responses were enhanced by reducing CD39 expression through the inhibition of the cAMP/PKA/p-CREB pathway, or by blocking adenosine signaling downstream of CD39 using the selective adenosine A2a receptor antagonist istradefylline. Thus, purinergic signaling in differentiating T cells can be targeted to improve vaccine responses, in particular in older individuals who have increased CD39 expression. 10.1172/JCI132417
    The role of the CD39-CD73-adenosine pathway in liver disease. Wang Sheng,Gao Songsen,Zhou Dexi,Qian Xueyi,Luan Jiajie,Lv Xiongwen Journal of cellular physiology Extracellular adenosine triphosphate (ATP) is a danger signal released by dying and damaged cells, and it functions as an immunostimulatory signal that promotes inflammation. The ectonucleotidases CD39/ectonucleoside triphosphate diphosphohydrolase-1 and CD73/ecto-5'-nucleotidase are cell-surface enzymes that breakdown extracellular ATP into adenosine. This drives a shift from an ATP-driven proinflammatory environment to an anti-inflammatory milieu induced by adenosine. The CD39-CD73-adenosine pathway changes dynamically with the pathophysiological context in which it is embedded. Accumulating evidence suggests that CD39 and CD73 play important roles in liver disease as critical components of the extracellular adenosinergic pathway. Recent studies have shown that the modification of the CD39-CD73-adenosine pathway alters the liver's response to injury. Moreover, adenosine exerts different effects on the pathophysiology of the liver through different receptors. In this review, we aim to describe the role of the CD39-CD73-adenosine pathway and adenosine receptors in liver disease, highlighting potential therapeutic targets in this pathway, which will facilitate the development of therapeutic strategies for the treatment of liver disease. 10.1002/jcp.29932
    On the mechanism of anti-CD39 immune checkpoint therapy. Allard David,Allard Bertrand,Stagg John Journal for immunotherapy of cancer With the coming of age of cancer immunotherapy, the search for new therapeutic targets has led to the identification of immunosuppressive adenosine as an important regulator of antitumor immunity. This resulted in the development of selective inhibitors targeting various components of the adenosinergic pathway, including small molecules antagonists targeting the high affinity A2A adenosine receptor and low affinity A2B receptor, therapeutic monoclonal antibodies (mAbs) and small molecules targeting CD73 and therapeutic mAbs targeting CD39. As each regulator of the adenosinergic pathway present non-overlapping biologic functions, a better understanding of the mechanisms of action of each targeted approach should accelerate clinical translation and improve rational design of combination treatments. In this review, we discuss the potential mechanisms-of-action of anti-CD39 cancer therapy and potential toxicities that may emerge from sustained CD39 inhibition. Caution should be taken, however, in extrapolating data from gene-targeted mice to patients treated with blocking anti-CD39 agents. As phase I clinical trials are now underway, further insights into the mechanism of action and potential adverse events associated with anti-CD39 therapy are anticipated in coming years. 10.1136/jitc-2019-000186
    Targeting CD39 in Cancer Reveals an Extracellular ATP- and Inflammasome-Driven Tumor Immunity. Li Xian-Yang,Moesta Achim K,Xiao Christos,Nakamura Kyohei,Casey Mika,Zhang Haiyan,Madore Jason,Lepletier Ailin,Aguilera Amelia Roman,Sundarrajan Ashmitha,Jacoberger-Foissac Celia,Wong Clifford,Dela Cruz Tracy,Welch Megan,Lerner Alana G,Spatola Bradley N,Soros Vanessa B,Corbin John,Anderson Ana C,Effern Maike,Hölzel Michael,Robson Simon C,Johnston Rebecca L,Waddell Nicola,Smith Corey,Bald Tobias,Geetha Nishamol,Beers Courtney,Teng Michele W L,Smyth Mark J Cancer discovery We explored the mechanism of action of CD39 antibodies that inhibit ectoenzyme CD39 conversion of extracellular ATP (eATP) to AMP and thus potentially augment eATP-P2-mediated proinflammatory responses. Using syngeneic and humanized tumor models, we contrast the potency and mechanism of anti-CD39 mAbs with other agents targeting the adenosinergic pathway. We demonstrate the critical importance of an eATP-P2X7-ASC-NALP3-inflammasome-IL18 pathway in the antitumor activity mediated by CD39 enzyme blockade, rather than simply reducing adenosine as mechanism of action. Efficacy of anti-CD39 activity was underpinned by CD39 and P2X7 coexpression on intratumor myeloid subsets, an early signature of macrophage depletion, and active IL18 release that facilitated the significant expansion of intratumor effector T cells. More importantly, anti-CD39 facilitated infiltration into T cell-poor tumors and rescued anti-PD-1 resistance. Anti-human CD39 enhanced human T-cell proliferation and Th1 cytokine production and suppressed human B-cell lymphoma in the context of autologous Epstein-Barr virus-specific T-cell transfer. SIGNIFICANCE: Overall, these data describe a potent and novel mechanism of action of antibodies that block mouse or human CD39, triggering an eATP-P2X7-inflammasome-IL18 axis that reduces intratumor macrophage number, enhances intratumor T-cell effector function, overcomes anti-PD-1 resistance, and potentially enhances the efficacy of adoptive T-cell transfer.. 10.1158/2159-8290.CD-19-0541