CD66a antibody targets the CD66a antigen, also known as CEACAM1 (Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1), a member of the CEACAM family. CEACAM1 is a transmembrane glycoprotein involved in cell adhesion, signaling, and immune regulation. It contains an N-terminal immunoglobulin (Ig)-like variable (IgV) domain, followed by multiple Ig-like constant (IgC2) domains, a transmembrane region, and a cytoplasmic tail with varying lengths due to alternative splicing. This structural diversity enables CEACAM1 to mediate both homophilic and heterophilic interactions, influencing processes like tumor suppression, angiogenesis, and immune cell modulation.
CD66a/CEACAM1 is expressed on epithelial, endothelial, and immune cells (e.g., T cells, neutrophils). It acts as a co-inhibitory receptor in T cells, dampening activation and cytokine production, which is critical in autoimmune diseases and cancer immune evasion. Its dysregulation is linked to tumor progression, chronic inflammation, and infections (e.g., *Neisseria* adhesion). CD66a antibodies are widely used in research to study CEACAM1's roles in immune tolerance, pathogen-host interactions, and cancer biology. They are employed in techniques like flow cytometry, immunohistochemistry, and functional blocking assays. Commercial CD66a antibodies are typically monoclonal, generated in mice or rats, and validated for specificity against recombinant or native CEACAM1 isoforms.