Bispecific c-Met/PD-1 CAR-T Cells Have Enhanced Therapeutic Effects on Solid Tumor

ObjectiveTo evaluate the killing effect of c-Met CAR-T on tumor cells with different degrees of c-Met expression. It was demonstrated that CAR-T autocrine PD-1 antibody could alleviate immune checkpoint inhibition and enhance the anti-tumor effect of T cells.MethodsThe specificity and clinical significance of c-Met and PD-L1 expression in various solid tumors were verified by bioinformatics analysis. c-Met specific CAR-T and c-Met specific CAR-T secreted by PD-L1 were synthesized, and c-Met CAR-T and c-Met/PD-1 CAR-T were prepared by constructing lentivirus. Flow cytometry was used to verify the positive rate and cell population of CAR-T, western blot was used to verify the secretion of PD-1 antibody, and cck-8 was used to detect the proliferation of CAR-T in tumor cells with different c-Met expression. LDH and ELISA further evaluated the antitumor effects of c-Met CAR-T and c-Met/PD-1 CAR-T in vitro.Resultsc-Met and PD-L1 were expressed in pancreatic cancer, ovarian cancer, esophageal cancer, bladder cancer, glioma and other tumors, and were associated with a variety of immune cell infiltration. Tumor cells with high expression of c-Met can strongly stimulate the proliferation of c-Met CAR-T, and c-Met CAR-T has strong cell lysis ability on tumor cells with high expression of c-Met. Autocrine PD-1 antibody can significantly improve the activity of c-Met CAR T cells, tumor lysis ability and cytokine secretion level.ConclusionThe antitumor activity of c-Met CAR-T is positively correlated with the expression of c-Met. c-Met CAR-T secreted by PD-1 showed enhanced antitumor function in solid tumor treatment.