Coupling programmed cell death 1-positive tumor-infiltrating T cells with anti-programmed cell death 1 antibody improves the efficacy of adoptive T-cell therapy

Background aims: Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has shown great success in clinical trials. Programmed cell death 1 (PD-1)-expressing TILs show high specificity to autologous tumor cells. However, limited therapeutic efficiency is observed as a result of the tumor immune microenvironment (TIME). Methods: Coupling PD-1(+) ex vivo-derived TILs with a monoclonal antibody against anti-PD-1 (aPD-1) reinvigorated the anti-tumor response of TILs against solid tumor without altering their high tumor targeting ability. Results: Using a melanoma-bearing mouse model, PD-1(+) TILs blocked with aPD-1 (PD-1(+) TILs-aPD-1) exhibited a high capability for tumor targeting as well as improved anti-tumor response in TIME. Tumor growth was substantially delayed in the mice treated with PD-1(+) TILs-aPD-1. Conclusions: The strategy utilizing TIL therapy coupled with immune checkpoint antibodies may extend to other therapeutic targets of ACT. (C) 2021 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.