Dasatinib-Resistant Universal CAR-T cells Proliferate in the Presence of Host Immune Cells and Exhibit Antitumor Activity

The universal chimeric antigen receptor T-cell (UCAR-T) immunotherapy derived from healthy donors holds great promise in pan-cancer treatment. However, UCAR-T cell therapy faces a challenge in the rapid elimination of allogeneic cells by the host immune system. To address this, we introduced a T316I mutation in the leukocyte-specific protein tyrosine kinase (LCK) locus in CAR-T cells using the cytosine base editor (CBE) system. Concurrently, we disrupted endogenous T-cell receptor alpha chain (TRAC) and beta-2 microglobulin (B2M) with the CRISPR-Cas9 system, along with dasatinib to overcome host immune rejection, an Src family kinase (SFK) inhibitor. The resulting LCK mutated UCAR-T (KM UCAR-T) cells exhibited normal phenotypes in activation, proliferation, differentiation, and tumor cytotoxicity in vitro. Moreover, KM UCAR-T cells demonstrated sustained expansion in mixed lymphocyte reactions (MLR) when incubated with T-cells or peripheral blood mononuclear cells (PBMCs) from HLA-mismatched donors upon dasatinib treatment. Additionally, we illustrated that KM UCAR-T cells displayed anti-tumor activity in a xenograft murine model and verified the expansion and cytotoxicity of KM UCAR-T over traditional UCAR-T in the presence of allogeneic PBMCs when treated with dasatinib in vivo. These findings offer a novel strategy for UCAR-T cells to resist host immune rejection and achieve sustained expansion.