CD52 glycoprotein (CD52)

CD52 is a small, heavily glycosylated protein (approximately 12 amino acids in the peptide core) anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage (UniProt, 2024; Wikipedia, 2024). It is expressed at high levels on the surface of mature lymphocytes (T and B cells), monocytes, and dendritic cells, as well as in the male reproductive tract (NIH, 2021). While its exact physiological role is not fully understood, it is involved in immune regulation, T-cell costimulation, and sperm maturation (NIH, 2021; Guide to Pharmacology, 2024). CD52 is a major therapeutic target for the monoclonal antibody alemtuzumab, which depletes CD52-positive cells through mechanisms like antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) (NIH, 2021; PatSnap, 2024). This depletion is clinically utilized to treat relapsing-remitting multiple sclerosis and certain hematologic malignancies like chronic lymphocytic leukemia (Wikipedia, 2024; NIH, 2020). However, targeting CD52 carries significant safety risks, including severe lymphopenia and the development of secondary autoimmune conditions such as thyroid disease and immune thrombocytopenia (NIH, 2021).

Other names

CAMPATH-1 antigenCDw52Cambridge pathology 1 antigenHE5Epididymal secretory protein E5Human epididymis-specific protein 5CD52 molecule

Antibody-dependent cellular cytotoxicity (ADCC), Complement-dependent cytotoxicity (CDC), and induction of apoptosis leading to rapid depletion of CD52-positive lymphocytes (NIH, 2021; PatSnap, 2024).