TRAIL-R1-targeted chimeric antigen receptor T cells exhibit dual antitumor effects

Tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) has limited expression in normal tissues but highly expression in a broad range of tumors, making it an attractive target for cancer immunotherapy. We have previously prepared a fully human monoclonal antibody targeting TRAIL-R1 (TR1419), which can specifically induce apoptosis in antigen-positive tumor cells. Here, we prepared the TR1419CAR-T cells using the single chain variable fragment (scFv) from TR1419, which were evaluated for the phenotypes and function. The TR1419CAR-T cells induced cytolysis of TRAIL-R1-positive tumor cells not only via activation of the death receptor-dependent apoptotic pathway, but also via T-cell mediated cytotoxicity. Furthermore, compared to the second-generation TR1419-28ζ and TR1419-BBζ CAR-T cells, the third-generation TR1419-28BBζ CAR-T cells had greater sensitivity to target antigen, exhibited a better proliferative ability, but showed slightly higher PD-1 expression after antigen stimulation. Altogether, TR1419CAR-T cells, especially TR1419-28BBζCAR-T cells could be a promising treatment strategy for TRAIL-R1 positive tumors.