Carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8) (CEACAM8)

Carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8), also known as CD66b, is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein belonging to the immunoglobulin superfamily (UniProt P31997). It is expressed exclusively on the surface of human granulocytes and their progenitors, making it a highly specific marker for mature neutrophils and granulocytic myeloid-derived suppressor cells (G-MDSCs) (NCBI Gene ID: 1088). Biologically, CEACAM8 mediates cell-cell adhesion through heterophilic interactions with other CEACAM family members, such as CEACAM6, and is involved in regulating neutrophil activation and degranulation (PubMed: 11544312). In clinical contexts, it is frequently used as a biomarker for neutrophil activation and to identify G-MDSCs within the tumor microenvironment, which are associated with poor prognosis in various cancers (PubMed: 25614318). While primarily used for diagnostic and research purposes, CEACAM8 is being explored as a potential therapeutic target for depleting immunosuppressive cells in cancer or for radioimmunotherapy in hematological malignancies. However, targeting CEACAM8 carries significant safety concerns, most notably the risk of systemic neutropenia and the subsequent impairment of host defense against bacterial and fungal infections.

Other names

CD66bCarcinoembryonic antigen gene family member 6CGM6CD67NCA-95

Antibody-mediated depletion of granulocytes via ADCC/ADCP or radioimmunotherapy-induced cell death; modulation of heterophilic cell-cell adhesion and signaling.