Cluster of differentiation 52 (CD52) (CD52)

Cluster of differentiation 52 (CD52) is a small, 12-amino-acid glycoprotein anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage. It is expressed at exceptionally high levels on the surface of mature T and B lymphocytes, as well as on natural killer cells, monocytes, and macrophages, but is notably absent from hematopoietic stem cells. While its exact physiological role is still being characterized, CD52 is believed to participate in immune regulation and lymphocyte migration, potentially acting as an anti-adhesion molecule to facilitate cell movement. CD52 is the primary therapeutic target of alemtuzumab, a humanized monoclonal antibody used in the treatment of B-cell chronic lymphocytic leukemia and relapsing-remitting multiple sclerosis. Binding of alemtuzumab to CD52 triggers the rapid and profound depletion of circulating lymphocytes through antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Despite its high efficacy in controlling neuroinflammation and malignant cell proliferation, targeting CD52 requires intensive monitoring due to risks of serious secondary autoimmune disorders and opportunistic infections.

Other names

CAMPATH-1 antigenCambridge pathology 1 antigenCDW52HE5EDDM5Epididymal secretory protein E5

Antibody-dependent cellular cytotoxicity (ADCC), Complement-dependent cytotoxicity (CDC), and induction of apoptosis leading to rapid depletion of CD52-expressing lymphocytes.