CD2 antigen (CD2)

CD2 antigen is a transmembrane cell surface glycoprotein predominantly expressed on all peripheral blood T cells, thymocytes, and natural killer (NK) cells. It functions as a costimulatory receptor that binds to its ligand LFA3 (CD58), which is widely expressed on various cell types including antigen-presenting cells. The primary roles of CD2 include facilitating adhesion between T cells and other immune cells, organizing the immunological synapse during immune responses, and enhancing signal transduction required for full activation of memory and effector T cells. Its expression is upregulated upon activation or in memory subsets. Clinically, CD2 serves as a pan–T cell marker useful in diagnosing lymphoid malignancies such as T-cell lymphoma. Therapeutically, it has been targeted by monoclonal antibodies to modulate undesired immune responses—such as in transplantation or autoimmune disease—though this approach carries risks related to global suppression of cellular immunity.

Other names

T-cell surface antigen CD2LFA-2LFA-3 receptorT11/Leu-5p50

Immune modulation via inhibition or activation of T cell function through blockade or engagement of the CD2/LFA3 pathway