Click CAR-T cell engineering for robustly boosting cell immunotherapy in blood and subcutaneous xenograft tumor

Abstract

The adoptive transfer of chimeric antigen receptor-T (CAR-T) cells has shown remarkable clinical responses in hematologic malignancies. However, unsatisfactory curative results and side effects for tumor treatment are still unsolved problems. Herein we develop a click CAR-T cell engineering strategy via cell glycometabolic labeling for robustly boosting their antitumor effects and safety in vivo. Briefly, paired chemical groups (N₃/BCN) are separately incorporated into CAR-T cell and tumor via nondestructive intrinsic glycometabolism of exogenous Ac₄GalNAz and Ac₄ManNBCN, serving as an artificial ligand-receptor. Functional groups anchored on cell surface strengthen the interaction of CAR-T cell and tumor via bioorthogonal click chemistry, further enhancing specific recognition, migration and selective antitumor effects of CAR-T cells. In vivo, click CAR-T cell completely removes lymphoma cells and minimizes off-target toxicity via selective and efficient bioorthogonal targeting in blood cancer. Surprisingly, compared to unlabeled cells, artificial bioorthogonal targeting significantly promotes the accumulation, deep penetration and homing of CAR-T cells into tumor tissues, ultimately improving its curative effect for solid tumor. Click CAR-T cell engineering robustly boosts selective recognition and antitumor capabilities of CAR T cells in vitro and in vivo, thereby holding a great potential for effective clinical cell immunotherapy with avoiding adverse events in patients.

Keywords: Bioorthogonal click chemistry; CAR-T cell; Cell immunotherapy; Glycometabolic labeling; Off-target effects.