CEACAM1 (Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily, widely expressed on epithelial, endothelial, and immune cells. It plays diverse roles in cell adhesion, intracellular signaling, and immune regulation. CEACAM1 interacts with homophilic and heterophilic ligands to modulate processes such as T-cell inhibition, angiogenesis, tumor suppression, and pathogen recognition. Its dual role in immunity—acting as both a coinhibitory receptor on T cells and a facilitator of microbial adhesion—makes it a molecule of significant interest in cancer, infectious diseases, and autoimmune disorders.
Antibodies targeting CEACAM1 are critical tools for studying its complex functions. In research, they are used to block interactions, detect expression patterns, or modulate signaling pathways. Therapeutically, CEACAM1 antibodies are explored in oncology to counteract immune evasion; for example, blocking CEACAM1's inhibitory signals on T cells may enhance antitumor responses. Conversely, some pathogens exploit CEACAM1 for host cell entry, prompting antibody development to prevent infection. Challenges include addressing its splice variants and context-dependent roles—pro-tumorigenic in certain cancers versus tumor-suppressive in others. Recent studies also highlight its involvement in metabolic regulation and checkpoint inhibitor resistance. CEACAM1 antibodies thus represent a versatile but nuanced avenue for both mechanistic studies and translational applications, requiring careful consideration of tissue-specific isoforms and microenvironmental influences.