Leukocyte surface antigen CD53 (CD53)

Leukocyte surface antigen CD53 is a cell surface glycoprotein of the tetraspanin family, predominantly expressed on various immune cells including B cells, T cells, monocytes, and natural killer cells[1][3][6]. CD53 functions as a structural component of tetraspanin-enriched microdomains, mediating protein–protein interactions that organize the cell membrane and facilitate signal transduction, adhesion, migration, and immune cell trafficking. It supports immune development, particularly B-cell and T-cell homing and activation, partly by stabilizing partner molecules such as L-selectin and modulating integrin complex function[3]. CD53 is structurally defined by four hydrophobic transmembrane domains and distinctive extracellular loops enabling specific partner interactions, with its open conformational state essential for enabling these interactions and supporting directional cell migration[2][5][6]. Genetic deficiency of CD53 can result in immunodeficiency with increased susceptibility to recurrent infections. CD53 is commonly used as a marker in immunophenotyping but is not currently the direct target of any approved therapeutic drugs[1][3].

Other names

Leukocyte surface antigen CD53MOX44TSPAN25Tspan-25Cell surface glycoprotein CD53Tetraspanin-25CD53 antigenCD53 glycoproteinCD53 tetraspan antigenantigen MOX44 (identified by monoclonal antibody MRC-OX44)cell surface antigentransmembrane glycoproteinCD53

Not applicable/known (no direct drugs; in the literature, primarily acts through protein–protein interactions within immune cell signaling networks and membrane organization)