CELL INTELLIGENCE · 肿瘤细胞治疗研究

Therapeutic strategies for peritoneal metastasis in solid tumors are urgently needed. Programming chimeric antigen receptor macrophages (CAR-Ms) in situ offers opportunities for an unmet demand. However, potential intracellular domains (ICDs) for CAR design and their antitumor mechanisms for macrophage empowerment remain to be explored systematically. By developing a macrophage-targeted mRNA lipid nanoparticle (mRNA-LNP) system, we evaluate 36 CAR formats in CAR-Ms. Tailored CAR-Ms with CD3ζ TLR4 ICDs elicit robust adaptive immune activation and significantly synergize with PD-1/L1 therapy. Single-cell RNA sequencing (scRNA-seq) reveals that CAR-Ms reshape the immunosuppressive tumor microenvironment (TME) and boost the TCF1 + PD-1 + progenitor-exhausted CD8 + T cells (Tpex) population. Mechanistically, CAR-Ms maintain a proinflammatory phenotype and simultaneously upregulate MHC-I and PD-L1 by perturbing NF-κB pathways. Collectively, this approach enables intraperitoneal programming of tailored CAR-Ms and broadens understanding of both regulatory and feedback mechanisms for CAR-M therapies against solid tumors.