Cieniewicz et al. transduced T cells to express the chimeric receptor CER-1236, consisting of the extracellular domain of TIM-4, which recognizes phosphatidylserine (PS) as a phagocytic target, fused with the intracellular signaling domains TLR2/TIR, CD28, and CD3ζ. CER-1236 T cells showed in vitro phagocytic and cytotoxic activity against MCL and EGFR-mutated NSCLC expressing PS, expression of which could be enhanced by treatment with BTK or EGFR inhibitors, respectively. CER-1236 T cells could cross-present antigens in in vitro assays, and infusion into NSG mice bearing MCL or NSCLC tumors induced tumor regression and improved survival.

Contributed by Maartje Wouters

ABSTRACT: To leverage complementary mechanisms for cancer cell removal, we developed a novel cell engineering and therapeutic strategy co-opting phagocytic clearance and antigen presentation activity into T cells. We engineered a chimeric engulfment receptor (CER)-1236, which combines the extracellular domain of TIM-4, a phagocytic receptor recognizing the "eat me" signal phosphatidylserine, with intracellular signaling domains (TLR2/TIR, CD28, and CD3ζ) to enhance both TIM-4-mediated phagocytosis and T cell cytotoxic function. CER-1236 T cells demonstrate target-dependent phagocytic function and induce transcriptional signatures of key regulators responsible for phagocytic recognition and uptake, along with cytotoxic mediators. Pre-clinical models of mantle cell lymphoma (MCL) and EGFR mutation-positive non-small cell lung cancer (NSCLC) demonstrate collaborative innate-adaptive anti-tumor immune responses both in vitro and in vivo. Treatment with BTK (MCL) and EGFR (NSCLC) inhibitors increased target ligand, conditionally driving CER-1236 function to augment anti-tumor responses. We also show that activated CER-1236 T cells exhibit superior cross-presentation ability compared with conventional T cells, triggering E7-specific TCR T responses in an HLA class I- and TLR-2-dependent manner, thereby overcoming the limited antigen presentation capacity of conventional T cells. Therefore, CER-1236 T cells have the potential to achieve tumor control by eliciting both direct cytotoxic effects and indirect-mediated cross-priming.

Author Info: (1) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (2) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (3) Cero Therapeutics Inc, South San Francisco, CA 940

Author Info: (1) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (2) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (3) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (4) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (5) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (6) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (7) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (8) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (9) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (10) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (11) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (12) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (13) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (14) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (15) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (16) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. (17) Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. (18) Cero Therapeutics Inc, South San Francisco, CA 94080, USA. Electronic address: dcorey@cero.bio.