Addressing unmet needs for CAR T cell efficacy in solid tumors, Hirabayashi, Du et al. designed a novel two-construct CAR T, with each construct targeting a distinct antigen and containing either aCD28 or 4-1BB costimulatory domain; only one carried a “shared” CD3ζ. In a neuroblastoma model, the dual CAR was efficacious under stress conditions, protected against rechallenge, and prevented tumor escape due to heterogenous antigen expression. RNAseq revealed a metabolic profile of CAR T cell proliferation undergoing glycolytic and oxidative metabolism, consistent with rapid effector T cell activity and long-term survival. The approach was validated using a second pair of targets.
Contributed by Katherine Turner
ABSTRACT: Chimeric antigen receptor (CAR)-T cells showed great activity in hematologic malignancies. However, heterogeneous antigen expression in tumor cells and suboptimal CAR-T-cell persistence remain critical aspects to achieve clinical responses in patients with solid tumors. Here we show that CAR-T cells targeting simultaneously two tumor-associated antigens and providing trans-acting CD28 and 4-1BB co-stimulation, while sharing the same CD3ζ-chain cause rapid antitumor effects in in vivo stress conditions, protection from tumor re-challenge and prevention of tumor escape due to low antigen density. Molecular and signaling studies indicate that T cells engineered with the proposed CAR design demonstrate sustained phosphorylation of T-cell-receptor-associated signaling molecules and a molecular signature supporting CAR-T-cell proliferation and long-term survival. Furthermore, metabolic profiling of CAR-T cells displayed induction of glycolysis that sustains rapid effector T-cell function, but also preservation of oxidative functions, which are critical for T-cell long-term persistence.
Author Info: (1) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. (2) Department of Pediatrics, University of
North Carolina at Chapel
Author Info: (1) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. (2) Department of Pediatrics, University of
North Carolina at Chapel Hill, Chapel Hill, NC, USA. (3) Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel
Hill, NC, USA. (4) These authors contributed equally: Koichi Hirabayashi, Hongwei Du. e-mail: hwdu@email.unc.edu; gdotti@med.unc.edu
