Multiple T-lymphocyte surface antigens and related cell-surface proteins (T-cell surface antigens)

Multiple T-lymphocyte surface antigens and related cell-surface proteins refer to a heterogeneous group of molecular entities expressed on the surface of human thymocytes and mature T-lymphocytes. This collective target is the primary focus of polyclonal antibody therapies such as Antithymocyte Globulin (ATG), which is derived from the serum of horses or rabbits immunized with human thymic tissue [FDA: Atgam Label; FDA: Thymoglobulin Label]. The specific proteins targeted include various Cluster of Differentiation (CD) markers such as CD2, CD3, CD4, CD8, CD11a, CD18, CD25, CD44, and CD45, as well as HLA Class I and II molecules [PubMed: Mohty M., 2007]. By binding to these diverse antigens simultaneously, the drugs induce profound and rapid immunosuppression through T-cell depletion and functional modulation. This multi-antigen approach is clinically essential for preventing and treating acute organ transplant rejection and managing severe aplastic anemia. However, because the targeting is broad and non-specific to a single pathway, it carries significant risks of systemic inflammatory reactions and long-term immune vulnerability [StatPearls: Antithymocyte Globulin, 2023].

Other names

Thymocyte antigensT-lymphocyte antigensATG targetsLymphocyte-selective antigens

Polyclonal antibodies bind to a wide array of T-cell surface proteins, leading to rapid lymphocyte depletion through complement-dependent lysis, opsonization followed by macrophage-mediated phagocytosis, and the induction of apoptosis. Additionally, these antibodies interfere with T-cell function by blocking receptors involved in cell signaling and adhesion [PubMed: Mohty M., 2007; StatPearls: Antithymocyte Globulin, 2023].