Editing genomico di linfociti T per contrastare l’effetto immunosoppressivo dell’adenosina nella terapia adottiva del tumore al colon-retto

Colorectal cancer (CRC) is the third most diagnosed cancer worldwide and the second leading cause of cancer-related death, which is mainly correlated to the development of metastatic disease, found in 20% of new-diagnosed CRC patients. Despite standard therapies, with surgery as the cornerstone treatment for localized tumors, the prognosis remains poor, especially upon metastatic progression. The CRC tumor microenvironment (TME) is relevantly involved in tumor progression: indeed, tumor infiltrating lymphocytes (TILs) play a central role in the immune response against cancer, and their presence correlates with improved patients’ overall survival. However, their functionality is closely intertwined with metabolic reprogramming within the TME, which supports the increased energy request of cancer cells while suppresses the effector function and cytokines production of the immune infiltrate, in particular T lymphocytes. Extracellular adenosine, accumulating in the TME for the sequential hydrolysis of ATP by ectonucleotidases CD39 and CD73, has been recently recognized as a new immune checkpoint mediator, which binds preferentially to A2A receptor (A2AR) to exert its immune-suppressive activity. With the aim of investigating the relevance of the adenosinergic axis in CRC, we firstly examined the expression landscape of CD39, CD73 and A2AR (adenosine-related markers, ARMs) in primary T cells derived from patients’ tumor samples and peripheral blood. T cells expressing CD39 and A2AR were particularly enriched within the tumor compared to the peripheral blood, and co-expressed PD-1. Giving the relevance of ARMs expression in TILs, we aimed at exploring the effects of metabolic reprogramming on adoptive T cell (ACT) products specifically redirected toward the HER2 tumor antigen, which is overexpressed in a subgroup of CRC patients. By CRISPR/Cas9 genome editing, we disrupted the α chain of the endogenous TCR (80% mean efficiency) in combination with ENTPD1 (CD39; 94% mean efficiency), NT5E (CD73; 70% mean efficiency) or ADORA2A (A2AR; 80% mean efficiency) in primary T cells. Upon disruption of each ARM, we observed variations of the protein expression of the other two adenosine-related markers in edited cells; this suggests a possible activation of compensatory mechanisms upon alteration of the ATP/Adenosine pathway. Importantly, almost all engineered T cells were not perturbed in their growth kinetics, CD4/CD8 ratio and memory differentiation after the genetic manipulation; only when disrupted in ADORA2A, T cells showed reduced proliferation. To functionally test edited T cell products, we redirected their specificity against the HER2 antigen by lentiviral transduction (60% mean efficiency) and challenged them with tumor cell lines and patient-derived organoids from primary and metastatic colorectal cancer. We showed edited T cells-mediated elimination of the tumors, with an increased killing ability of ENTPD1-disrupted T cells compared to NT5E- or A2AR-disrupted or α chain single-edited T cells. We further tested TCREDENTPD1KOHER2 T lymphocytes antitumoral activity in vivo in a subcutaneous and an orthotopic mouse model of CRC liver metastases. In both models, HER2-redirected, ENTPD1-disrupted T cells outperformed TCREDHER2 T cells in the capacity of controlling tumor growth. Taken together, these data suggest a promising role for the editing of ARMs genes in ACT, with CD39 as the best target. Further characterization will be needed to understand molecular mechanisms underlying this functional advantage, together with the testing of our cellular products under immune-suppressive conditions mimicking the CRC TME.