CEACAM8. also known as CD66b, is a member of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family, which comprises glycoproteins involved in cell-cell interactions, immune regulation, and pathogen binding. Primarily expressed on the surface of granulocytes (neutrophils, eosinophils) and their precursors, CEACAM8 functions as an activation marker during inflammation. Its structure includes an N-terminal immunoglobulin (Ig)-like variable (IgV) domain that mediates homophilic and heterophilic interactions, followed by multiple Ig constant-like (IgC) domains anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage.
Antibodies targeting CEACAM8 are widely used in research to study granulocyte activation, trafficking, and effector functions in inflammatory diseases (e.g., sepsis, asthma) and cancer. These antibodies enable detection of CEACAM8 expression via flow cytometry, immunohistochemistry, or Western blotting, aiding in the identification of activated neutrophils in tissue samples or peripheral blood. Additionally, CEACAM8-specific antibodies have been employed to investigate its role in modulating immune responses, such as regulating neutrophil apoptosis or enhancing phagocytosis. In clinical contexts, CEACAM8 expression levels may serve as a biomarker for disease severity or therapeutic response. However, its precise biological roles and signaling pathways remain under exploration, particularly regarding cross-talk with other CEACAM family members (e.g., CEACAM1) and implications in bacterial adhesion or immune evasion. Monoclonal antibodies against CEACAM8 continue to be vital tools for dissecting its contributions to innate immunity and inflammation.