Comprehensive structural optimization of chimeric antigen receptors (CARs) is the key to their successful performance both in vitro and in vivo. In order to compare various CAR designs in an unified format, we took advantage of a lentiviral platform, where all CAR modules can be easily shuffled and tested for functionality. This platform was used to delineate the effects of various spacer regions on the function of a PSCA-specific CAR in the context of a human NK cell line, YT. We show that three CAR designs (IgG1-, CD8a-, and spacerless) perform similarly in vitro regardless of the length of the spacer region.

Chimeric antigen receptor (CAR), adoptive immunotherapy, prostate cancer, prostate stem cell antigen (PSCA).