T cell surface glycoprotein CD2 (CD2)

T cell surface glycoprotein CD2 is a 50–55 kDa transmembrane protein expressed on nearly all peripheral blood T lymphocytes, most thymocytes, and natural killer (NK) cells. It belongs to the immunoglobulin superfamily with two extracellular Ig-like domains. Its primary functions are mediating adhesion between T/NK cells and other immune or target cells via binding to ligands such as LFA‑3/CD58 on antigen-presenting or target cells, facilitating formation of the immunological synapse essential for effective immune responses. Beyond adhesion, it acts as a co-stimulatory molecule enhancing signal transduction during antigen recognition by the TCR complex. Clinically, it serves as an important marker for diagnosing lymphoid malignancies involving mature T or NK lineages; experimental therapies have targeted this pathway for modulating immunity but face challenges due to its broad physiological roles.[1][3][4][5][6][7]

Other names

T-cell surface antigen T11/Leu-5LFA-2LFA-3 receptorErythrocyte receptorRosette receptorSRBC[3][6][7][9]

Drugs or antibodies targeting CD2 generally act by blocking its interaction with LFA‑3/CD58 to inhibit T cell adhesion and co-stimulation, thereby reducing immune activation. Some monoclonal antibodies can also trigger signaling through CD2 to modulate immune responses[1][3].