UCLA

CAR-T cell therapy has emerged as a promising cancer treatment modality with curative potential. In this therapeutic regime, T cells are isolated from patient blood, genetically engineered to express tumor-targeting chimeric antigen receptors (CARs), and re-infused back into the patient as a living drug. As living drugs, CAR-T cells have the unique capacity of being able to sense-and-respond to a variety of pathologic stimuli in order to safely and effectively eliminate cancer cells. Furthermore, CAR-T cells can be genetically engineered to execute researcher-defined genetic programs – be it Boolean logic processing in the presence of multiple antigen targets, or straightforward execution of robust T-cell effector responses. Despite clinical success in treating hematological malignancies, CAR-T cells have had limited efficacy in treating vast the majority of cancers, comprising of solid tumors. Two major barriers include CAR target antigen choice and suboptimal persistence of CAR-T cells. First, because cancer cells are derived from “self”, tumor-exclusive surface antigens that are absent on all other cells are scarce. In practice, tumor-associated antigens are commonly selected as CAR targets, but clinical experience has shown that “on-target, off-tumor” CAR-T cell killing can lead to fatal outcomes. In order to overcome this, we attempt to reprogram the CAR-T cell killing machinery by engineering CAR-T cells to sense-and-respond to intracellular proteins, thereby expanding the repertoire of targetable antigens. Second, suboptimal receptor design and T-cell manufacturing methodologies can limit the anti-tumor efficacy of adoptively transferred CAR-T cells. In order to address this, we dissect the transcriptomes of high- and low-performing CAR-T cells to understand the molecular pathways undermining robust CAR-T cell function, where we identify histone deacetylation as a contributor in driving CAR-T cell dysfunction. We further identify CAR tonic signaling as a guide for rational CAR design and as a druggable signaling pathway that, when minimized, enhances anti-tumor efficacy. Collectively, the work presented in this dissertation provides steps towards outsmarting and outmuscling cancer cells by laying the foundation for reprogramming CAR-T to recognize intracellular antigens and by modulating antigen-independent CAR-T cell signaling pathways for enhanced tumor-killing efficacy.