Immune cell surface antigen

Immune cell surface antigens are molecular markers located on the exterior membranes of immune cells, such as lymphocytes (T cells, B cells, NK cells), monocytes, macrophages, dendritic cells, and granulocytes. These molecules determine the phenotypic identity and function of the cells by participating in differentiation, activation, signaling, and cell-to-cell interactions. Commonly characterized as “CD” markers (Cluster of Differentiation numbers, e.g., CD4, CD8, CD20), these antigens allow for the classification and study of immune cell subsets and are widely used as tools for flow cytometry, immunohistochemistry, and targeted therapy. Many surface antigens are directly targeted by modern immunotherapeutics, making them highly relevant for research, diagnostics, and treatment across cancer, autoimmune, infectious, and inflammatory diseases.

Other names

Surface immunological markersdifferentiation antigensCD antigens (Cluster of Differentiation)cell surface markersimmune cell markers

Mechanisms include immune cell depletion (e.g., antibody-dependent cell-mediated cytotoxicity), immune cell activation or inhibition (agonism or antagonism of receptor/marker), immunomodulation (alteration of signaling pathways), and cell lysis (complement-dependent cytotoxicity). The specific mechanism depends on the individual surface antigen targeted.