CD39 expression on CD8+ Tumor-infiltrating T cells is associated to effector memory phenotype and metabolic stress.

FELIX CONDAT; FERNANDO CANALE; SABRINA BOSSIO; CAROLINA ABRATE; ADRIANA GRUPPI; EVA ACOSTA RODRIGUEZ; CAROLINA MONTES

Mar del Plata

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Inmunología; 2018

Sociedad Argentina de Inmunología

The ability of CD8+ T lymphocytes to eliminate tumors is limited by their ability to engenderan immunosuppressive microenvironment. Previously we have described a subset of tumor-infiltrating CD8+ T cells marked by high expression of the immunosuppressive ATP ecto-nucleotidase CD39. The frequency of CD39highCD8+ T cells increased with tumor growth but was absent in lymphoid organs. Tumor-infiltrating CD8+ T cells with high CD39 expression exhibited features of exhaustion, such as reduced production of TNF and IL-2 and expression of co-inhibitory receptors. In specimens from breast cancer and melanoma patients, CD39+CD8+ T cells were present within tumors and invaded or metastatic lymph nodes, but were barely detectable within non-invaded lymph nodes and absent in peripheral blood (Canale et al., Cancer Research 2018). CD39 emerges as marker of T cell exhaustion and activation and may implicate the purinergic pathway in the regulation of T cell exhaustion.