Fig. 3
From: Universal CARs, universal T cells, and universal CAR T cells
The structure of SUPRA CAR. A SUPRA CAR system consists of a zipCAR and a zipFv. A zipFv has a scFv linked to a leucine zipper (AZip). A zipCAR has a cognate leucine zipper (BZip) that can bind to the AZip. Through the binding between A- and B-leucine zippers, any extracellular signal linked to the AZip can activate the T cells. Therefore, the SUPRA CAR remains constant and can serve as a universal CAR. The affinity between the A- and B-leucine zippers can be adjusted so that the signaling strength and activity can be dialed up or down as desired. When AZip is linked to a null antigen, the signaling is quenched, and T cells become inactive. (adapted from Choi, JH, et al., Cell 2018; 173: 1–13)