Genetic deletion of PD-1 enhances anti-tumor T cell therapy

Researchers from University College London (UCL) Cancer Institute and Cellectis S.A. (Euronext: ALCLS; NASDAQ: CLLS) published mouse data showing that gene editing to inactivate PD-1 in T cells isolated for adoptive cell therapy can boost the cells' anti-tumor effects -- a strategy the team believes can avoid adverse events caused by systemic immunotherapy with checkpoint inhibitors.

In a study published Friday in Cancer Research, the team isolated CD4+ and CD8+ T cells from tumor and tumor-draining lymph node tissues in a mouse model of fibrosarcoma, and transfected the cells with mRNA encoding transcription activator-like effector nucleases (TALENs) targeting PD-1. Tumor-bearing mice receiving the PD-1-deficient cells had decreased tumor growth and prolonged survival compared with those receiving T cells transfected with control mRNA. The authors attributed the effect to the modified T cells' greater persistence in the tumor. ...