CEACAM1 is an inhibitory macrophage immune checkpoint via homophilic engagement

ABSTRACT: Macrophage-mediated tumor cell phagocytosis is an important component of tumor immunosurveillance, yet the mechanisms by which tumors evade macrophage-mediated clearance remain incompletely understood. In this study, we identified CEACAM1 as an inhibitory macrophage immune checkpoint that suppresses tumor cell phagocytosis through homophilic CEACAM1 engagement between tumor cells and macrophages. To investigate how tumor-cell CEACAM1 affects the tumor immune microenvironment, we performed single-cell RNA sequencing of CD45⁺ tumor-infiltrating immune cells isolated from CtrlKO and CEACAM1KO E0771 tumors grown in C57BL/6 mice. Single-cell transcriptomic analysis revealed that CEACAM1 deficiency remodeled both myeloid and T-cell compartments, including a reduction in immunosuppressive tumor-associated macrophages and enrichment of tumor-suppressive, antigen-presenting, and inflammatory myeloid populations. These data provide a single-cell transcriptomic resource for understanding how CEACAM1-mediated phagocytosis inhibition shapes antitumor immunity within the tumor microenvironment.

ORGANISM(S): Mus musculus

PROVIDER: GSE346947 | GEO | 2026/10/06

REPOSITORIES: GEO