Biology subjects

Klysz, D.

Publications and source records attributed to Klysz, D..

2 recordsLinked to original sources

bioRxiv2022

Enhanced Effector Activity of Mediator Kinase Module Deficient CAR-T Cells

Adoptive T cell immune therapies mediate impressive clinical benefit in a fraction of patients, but anti-tumor effects are often limited by inadequate T cell potency. To identify genes limiting T cell effector function, we conducted genome-wide CRISPR knock-out screens in human primary CAR-T cells. The top hits were MED12 and CCNC, components of the cyclin-dependent kinase (CDK) module of the Mediator complex, an evolutionarily conserved regulator of gene transcription. MED12 or CCNC deficient CAR-T cells manifest increased expansion, cytokine production, metabolic fitness, effector function, anti-tumor activity and reduced terminal effector differentiation. Chemical inhibition of CDK8/19 kinase activity recapitulated some features of genetic loss of MED12, including increased T cell expansion. MED12 deficient CAR-T cells showed widespread but selective increases in chromatin accessibility, MED1 chromatin occupancy, and H3K27 acetylation at enhancers used by transcription factors playing a critical role in T cell fate, including several STAT and AP1 family members. The most pronounced enhancement was observed for STAT5 which manifested as increased sensitivity to IL-2 in MED12 deficient T cells. These results link Mediator induced transcriptional coactivation with T cell effector programming and identify the CDK module as a target for enhancing the potency of anti-tumor T cell responses. One Sentence SummaryThe Mediator kinase module is a primary regulator of T cell differentiation, and genetic or small molecule-based inhibition of this module enhances effector T cell potency.

immunology↗

bioRxiv2022

Coopting T cell proximal signaling molecules enables Boolean logic-gated CAR T cell control

Introductory paragraphWhile CAR T cells have altered the treatment landscape for B cell malignancies, the risk of on-target, off-tumor toxicity has hampered their development for solid tumors because most target antigens are shared with normal cells1,2. Researchers have attempted to apply Boolean logic gating to CAR T cells to prevent on-target, off-tumor toxicity3-7; however, a truly safe and effective logic-gated CAR has remained elusive8. Here, we describe a novel approach to CAR engineering in which we replace traditional ITAM-containing CD3{zeta} domains with intracellular proximal T cell signaling molecules. We demonstrate that certain proximal signaling CARs, such as a ZAP-70 CAR, can activate T cells and eradicate tumors in vivo while bypassing upstream signaling proteins such as CD3{zeta}. The primary role of ZAP-70 is to phosphorylate LAT and SLP-76, which form a scaffold for the propagation of T cell signaling. We leveraged the cooperative role of LAT and SLP-76 to engineer Logic-gated Intracellular NetworK (LINK) CAR, a rapid and reversible Boolean-logic AND-gated CAR T cell platform that outperforms other systems in both efficacy and the prevention of on-target, off-tumor toxicity. LINK CAR will dramatically expand the number and types of molecules that can be targeted with CAR T cells, enabling the deployment of these powerful therapeutics for solid tumors and diverse diseases such as autoimmunity9 and fibrosis10. In addition, this work demonstrates that the internal signaling machinery of cells can be repurposed into surface receptors, a finding that could have broad implications for new avenues of cellular engineering.

synthetic biology↗