Single Cell Spatial Analysis Reveals the Topology of Immunomodulatory Purinergic Signaling in Glioblastoma

Glioblastoma develops an immunosuppressive microenvironment that fosters tumorigenesis and resistance to current therapeutic strategies. Here we use multiplexed tissue imaging and single-cell RNA-sequencing to characterize the composition, spatial organization, and clinical significance of extracellular purinergic signaling in glioblastoma. We show that glioblastoma exhibit strong expression of CD39 and CD73 ectoenzymes, correlating with increased adenosine levels. Microglia are the predominant source of CD39, while CD73 is principally expressed by tumor cells, particularly in tumors with amplification of EGFR and astrocyte-like differentiation. Spatially-resolved single-cell analyses demonstrate strong spatial correlation between tumor CD73 and microglial CD39, and that their spatial proximity is associated with poor clinical outcomes. Together, this data reveals that tumor CD73 expression correlates with tumor genotype, lineage differentiation, and functional states, and that core purine regulatory enzymes expressed by neoplastic and tumor-associated myeloid cells interact to promote a distinctive adenosine-rich signaling niche and immunosuppressive microenvironment potentially amenable to therapeutic targeting.

Influence of Zika Virus in mechanisms related of cytotoxicity, cell adhesion, apoptosis and inflammatory markers on glioblastoma cells

Glioblastoma (GBM) is one of the most common brain tumors in adults. Despite the presence of available treatments, it remains one of the most lethal and difficult tumors to treat such that most patients die within two years. Studies reported that infection with Zika virus (ZIKV) causes inhibition of cell proliferation as well as induction of apoptosis; moreover, these manifestations show a predilection for developing neuronal cells. In the present study, two GBM cell lines U-138 and U-251 were infected with ZIKV at multiplicities of infection (MOI) 0.1, 0,01 and 0.001 and tested for cell viability, cell migration, cell adhesion, induction of apoptosis, interleukin levels, and cell surface markers (CD14 and CD73). Our study demonstrated that the ZIKV infection promotes loss of cell viability and increased apoptosis potential. It was not evidenced changes in cell migration, however, the two glioblastoma cell lines displayed increased the cell adhesion behavior. There was small increase in the IL-4 level in the U-251 cell line after exposure to ZIKV, with no change in relation to INF-γ levels. Furthermore, we observed an increase in the percentage of cells expressing the CD14 surface marker in both cell lines and increased CD73 expression in the U-251 cell line. Our results suggest that ZIKV may be associated with decrease of cell viability and increased CD73 expression, enhanced adherence, as well as increased apoptosis rates. Further investigations are required to explore the potential use of ZIKV in the treatment of GBM.

Amplification of spatially isolated adenosine pathway by tumor–macrophage interaction induces anti-PD1 resistance in hepatocellular carcinoma

Background Immune checkpoint blockade resistance narrows the efficacy of cancer immunotherapies, but the underlying mechanism remains elusive. Delineating the inherent mechanisms of anti-PD1 resistance is important to improve outcome of patients with advanced HCC. Method The level of cricTMEM181 was measured in HCC patients with anti-PD1 therapy by RNA sequencing and then confirmed by qPCR and Sanger sequencing. Immune status in tumor microenvironment of HCC patients or mice models was evaluated by flow cytometry and IHC. Exosomes from HCC cell lines were isolated by ultracentrifugation, and their internalization by macrophage was confirmed by immunofluorescence. The underlying mechanism of HCC-derived exosomal circTMEM181 to macrophage was confirmed by SILAC, RNA FISH and RNA immunoprecipitation. The ATP–ADO pathway amplified by HCC–macrophage interaction was evaluated through ATP, AMP and ADO measurement and macrophage-specific CD39 knockout mice. The role of circTMEM181 in anti-PD1 therapy and its clinical significance were also determined in our retrospective HCC cohorts. Results Here, we found that circTMEM181 was elevated in hepatocellular carcinoma (HCC) patients responding poorly to anti-PD1 therapy and in HCC patients with a poor prognosis after operation. Moreover, we also found that high exosomal circTMEM181 favored the immunosuppressive microenvironment and endowed anti-PD1 resistance in HCC. Mechanistically, exosomal circTMEM181 sponged miR-488-3p and upregulated CD39 expression in macrophages. Using macrophage-specific CD39 knockout mice and pharmacologic approaches, we revealed a novel mode of anti-PD1 resistance in HCC. We discovered that cell-specific CD39 expression in macrophages and CD73 expression in HCC cells synergistically activated the eATP–adenosine pathway and produced more adenosine, thereby impairing CD8+ T cell function and driving anti-PD1 resistance. Conclusion In summary, HCC-derived exosomal circTMEM181 contributes to immunosuppression and anti-PD1 resistance by elevating CD39 expression, and inhibiting the ATP–adenosine pathway by targeting CD39 on macrophages can rescue anti-PD1 therapy resistance in HCC. Graphical Abstract

CD73-Mediated Immunosuppression Is Linked to a Specific Fibroblast Population That Paves the Way for New Therapy in Breast Cancer

Background: Cancer-associated fibroblasts (CAF) are heterogeneous with multiple functions in breast cancer. Recently, we identified a specific CAF subpopulation (referred to as CAF-S1), which promotes immunosuppression and immunotherapy resistance. Methods and Results: Here, by studying a large collection of human samples, we highlight the key function of CD73/NT5E in CAF-S1-mediated immunosuppression in breast cancer. We first reveal that CD73 protein level specifically accumulates in CAF-S1 in breast cancer patients. Interestingly, infiltration of regulatory T lymphocytes (Tregs) is significantly correlated with CD73 expression in stroma but not in epithelium, indicating that CD73 contributes to immunosuppression when expressed in CAF-S1 and not in tumor cells. By performing functional assays based on relevant systems using primary CAF-S1 isolated from patients, we demonstrate that CAF-S1 increase the content in both PD-1+ and CTLA-4+ Tregs. Importantly, the use of a blocking anti-CD73 antibody on CAF-S1 reduces CAF-S1-mediated immunosuppression by preventing expression of these immune checkpoints on Tregs. Conclusions: Our data support the potential clinical benefit of using both anti-CD73 and immune-checkpoint inhibitors in breast cancer patients for inhibiting CAF-S1-mediated immunosuppression and enhancing anti-tumor immune response.

CD73 Severed as a Potential Prognostic Marker and Promote Lung Cancer Cells Migration via Enhancing EMT Progression

To investigate the expression levels and prognostic value of CD73 in lung cancer. And moreover, to identify the effect and potential mechanism of CD73 on lung cancer cells proliferation and migration. CD73 expression levels in lung cancer were analyzed base on GEPIA2 and GEO database. GEPIA2 and Kaplan-Meier Plotter (KM Plotter) was used to analyzed the correlation between CD73 expression and prognosis. GEO dataset were analyzed via GEO2R. CD73 overexpression cell model was construction via recombinant lentivirus transfection into A549 and NCI-H520 cells. CCK8 assay were used to investigate cells proliferation. Migration and invasion ability were evaluated by scratch and transwell methods. Base on GEPIA2, GSE32683, GSE116959 and GSE37745 dataset, we found that CD73 expression were significant higher in tumor tissues of lung adenocarcinoma (LUAD) compared with that in non-tumor normal tissues and in lung squamous cell carcinoma (LUSC), while there were no significant difference of CD73 expression between LUSC and normal control tissues. Interestingly, a high CD73 level predict poor overall survival (OS) of LUSC. However, GEPIA2 and KM plotter showed the opposite conclusion of prognostic value of CD73 in LUAD. By using cell experiments, we found that CD73 overexpression promoted proliferation and migration of LUAD A549 cells. However, there was no significant effect of CD73 overexpression on LUSC NCI-H520 cells. Furthermore, CD73 overexpression facilitates epithelial to mesenchymal transition (EMT) progression of A549 cells. In conclusion, our results indicated that CD73 expression were increased in LUAD and might be an poor prognostic marker for LUSC patients. CD73 play an important role in LUAD cells proliferation and migration. These data allowed to support CD73 as a therapeutic target for LUAD.

CD73-positive extracellular vesicles promote glioblastoma immunosuppression by inhibiting T-cell clonal expansion

Extracellular vesicles are involved in the occurrence, progression and metastasis of glioblastoma (GBM). GBM can secrete a variety of tumour-derived extracellular vesicles (TDEVs) with high immunosuppressive activity that remotely suppress the systemic immune system, and therapy targeting TDEVs has potential efficacy. In this study, we detected a higher concentration of CD73+ TDEVs enriched in exosomes in central and peripheral body fluids of GBM patients than in those of patients with other brain tumours (low-grade glioma or brain metastases from melanoma or non-small-cell lung cancer). High CD73 expression was detected on the surface of T cells, and this CD73 was derived from TDEVs secreted by GBM cells. In vitro, we observed that CD73+ TDEVs released by GBM cell lines could be taken up by T cells. Moreover, excess adenosine was produced by AMP degradation around T cells and by adenosine receptor 2A (A2AR)-dependent inhibition of aerobic glycolysis and energy-related metabolic substrate production, thereby inhibiting the cell cycle entry and clonal proliferation of T cells. In vivo, defects in exosomal synthesis and CD73 expression significantly inhibited tumour growth in GBM tumour-bearing mice and restored the clonal proliferation of T cells in the central and peripheral regions. These data indicate that CD73+ TDEVs can be used as a potential target for GBM immunotherapy.

701 Activating CD73 on B cells as a target for immunotherapy of COVID-19 and viral associated cancers: clinical activity in human papilloma virus positive (HPV) head and neck squamous cell cancers (HNSCC)

BackgroundMupadolimab (mupa) is a humanized FcγR binding-deficient IgG1 anti-CD73 antibody that has agonistic properties.1 CD73 is involved in production of adenosine and in cellular trafficking. Mupa reacts with the majority of circulating B cells leading to activation and expression of differentiation markers CD69, CD138 and CD38, and transformation into plasmablasts with secretion of IgM and IgG. B cell activation provided the rationale to develop mupa for immunotherapy of cancer and Covid-19. Intratumor HPV specific B cells have been reported in HNSCC.2 This report describes properties of mupa and the early signs of clinical activity in HPV+ HNSCC.MethodsELISA and flow cytometry were used to measure binding of anti-CD73. Humanized NSG-SGM3 mice were used to evaluate effects of Mupa on human anti-SARS CoV2 spike protein (SP) response. CD73 expression in biopsies was measured by immunohistochemistry. Mupa (IV q 3 weeks) with or without pembrolizumab is being evaluated in an ongoing phase 1 trial in patients with refractory cancers.ResultsMupa binding to CD73 was blocked by APCP, an analog of adenosine diphosphate that locks CD73 in the closed conformation, indicating mupa binding to the open conformation. Cross blocking and cellular internalization studies showed that mupa is distinct from other anti-CD73 antibodies such as MEDI9447 and AD2. NSG-SGM3 mice were immunized with 50 µg SP subcutaneously and treated with mupa 10mg/kg or control IgG IP. Mupa treated animals mounted an antigen specific human anti-SP response; no antibody responses were seen in controls (P=0.02). In the dose-escalation portion of the phase 1 trial, mupa doses of ≥12 mg/kg saturated CD73 sites on circulating B cells. High stromal CD73 expression was observed in HPV+ HNSCC biopsies from 5 evaluable patients with chemotherapy and anti-PD1 refractory disease, and tumor regression was seen in 2 of these patients receiving 7 and 16 cycles of ≥12 mg/kg mupa without pembrolizumab. Safety of mupa+pembrolizumab was evaluated in 16 patients with no MTD reached and no changes in serum immunoglobulins. Transient reductions in circulating CD73 B cells were observed consistent with redistribution to lymphoid tissues.ConclusionsCD73 plays a role in B cell activation and differentiation. Mupa is an antibody with agonistic activity that stimulates B cells and enhances antigen specific antibody production. This activity supports a strategy to combine mupa with pembrolizumab to enhance both humoral and cellular immunity in the treatment of viral associated cancers such as HPV+HNSCC, and viral infections.Trial RegistrationNCT03454451ReferencesWillingham S, Criner G, Hill C, Hu S, Rudnick J, Daine-Matsuoka B, Hsieh J, Mashhedi H, Hotson A, Brody J, Marron T, Piccione E, Buggy J, Mahabhashyam S, Jones W, Mobasher M, Miller R. Characterization and Phase 1 trial of a B cell activating anti-CD73 antibody for the immunotherapy of COVID-19. medRxiv, 2020; https://doi.org/10.1101/2020.09.10.20191486.Wieland A, Patel M, Cardenas M, Eberhardt C, Hudson W, Obeng R, Griffith C, Wang X, Chen Z, Kissick H, Saba N, Ahmed R. Defining HPV-specific B cell responses in patients with head and neck cancer. Nature 2020; https://doi.org/10.1038/s41586-020-2931-3.Ethics ApprovalThe study was approved by Western IRB, approval number 1-1066703-1. Participants gave informed consent before taking part.

Therapeutically expanded human regulatory T-cells are super-suppressive due to HIF1A induced expression of CD73

The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression. In conjunction with CD39, CD73 expression enables expanded Tregs to convert ATP to immunosuppressive adenosine. We conclude that for maximum therapeutic benefit, Treg expansion protocols should be optimised for CD39/CD73 co-expression.