CD50. also known as ICAM-3 (Intercellular Adhesion Molecule-3), is a cell surface glycoprotein belonging to the immunoglobulin superfamily. It is constitutively expressed on leukocytes, including T cells, dendritic cells, and neutrophils. As a ligand for the β2-integrin LFA-1 (lymphocyte function-associated antigen-1), CD50 plays a critical role in cell-cell adhesion, immune cell interactions, and immune activation. It facilitates initial T cell-antigen-presenting cell (APC) contact during antigen recognition and supports immunological synapse formation.
CD50 antibodies are tools used to study immune regulation, inflammatory responses, and leukocyte trafficking. They can block CD50-LFA-1 interactions, modulating T cell activation and migration. In research, these antibodies help elucidate mechanisms in autoimmune diseases, chronic inflammation, and cancer immunotherapy. For example, CD50 expression is altered in certain leukemias and lymphomas, making it a potential diagnostic or therapeutic target.
Therapeutic applications of anti-CD50 antibodies are under exploration, particularly in targeting leukocyte adhesion in inflammatory disorders or enhancing immune responses against tumors. However, their clinical use remains investigational, with studies focusing on safety and efficacy in modulating immune pathways. Understanding CD50's role in immune homeostasis continues to drive interest in its antibody-based targeting for immunotherapy.