Engineering ‘off-the-shelf’ CAR-T cells resistant to biochemical and immunological barriers in the solid tumor microenvironment 2279

Abstract Description Chimeric Antigen Receptor (CAR) T cells have induced remarkable clinical responses in patients with hematological cancers. However, CAR-T therapies against solid tumors have not elicited similar outcomes because immunosuppressive barriers in the tumor microenvironment (TME) effectively attenuate anti-tumor activity. Here, we developed a multifaceted approach to engineer allogeneic (‘off-the-shelf’) CAR-T cells resistant to both biochemical (hypoxia-adenosinergic) and immunological (PD-L1 and TGF-β) inhibitory signaling using an adenine base editor and a CRISPR-Cas12b nuclease. The resulting CAR-T product comprised a combination of six gene edits to evade allorejection (B2M, CIITA), prevent graft-versus-host disease (CD3E) and resist biochemical (ADORA2A) and immunological (PDCD1, TGFBR2) negative regulation. This novel combinatorial genetic disruption in CAR-T cells enabled anti-tumor efficacy leading to improved tumor elimination and survival in humanized mouse models recapitulating a human TME. Our unique strategy conferred CAR-T cells resistance to a diverse TME and may unlock the therapeutic potential of CAR-T cells against solid tumors. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)