CRISPR/Cas9 mediated deletion of the adenosine A2A receptor enhances CAR T cell efficacy.

Adenosine is an immunosuppressive factor that limits anti-tumor immunity through the suppression of multiple immune subsets including T cells via activation of the adenosine A _2A receptor (A _2A R). Using both murine and human chimeric antigen receptor (CAR) T cells, here we show that targeting A _2A R with a clinically relevant CRISPR/Cas9 strategy significantly enhances their in vivo efficacy, leading to improved survival of mice. Effects evoked by CRISPR/Cas9 mediated gene deletion of A _2A R are superior to shRNA mediated knockdown or pharmacological blockade of A _2A R. Mechanistically, human A _2A R-edited CAR T cells are significantly resistant to adenosine-mediated transcriptional changes, resulting in enhanced production of cytokines including IFNγ and TNF, and increased expression of JAK-STAT signaling pathway associated genes. A _2A R deficient CAR T cells are well tolerated and do not induce overt pathologies in mice, supporting the use of CRISPR/Cas9 to target A _2A R for the improvement of CAR T cell function in the clinic.