Multiple T-lymphocyte and immune cell surface antigens (ATG targets)

Multiple T-lymphocyte and immune cell surface antigens represent a heterogeneous group of proteins expressed on the surface of lymphocytes, including CD2, CD3, CD4, CD8, CD11a, CD18, CD25, CD44, CD45, and HLA molecules (FDA Label: Thymoglobulin). These antigens are the collective targets of antithymocyte globulin (ATG), a polyclonal antibody therapy derived from rabbits or horses immunized with human thymocytes (StatPearls NBK538224). Biologically, these surface proteins mediate critical processes such as antigen recognition, T-cell activation, and leukocyte adhesion to the vascular endothelium. In clinical pathology, these antigens are involved in the T-cell mediated attack against allogeneic grafts and the destruction of hematopoietic stem cells in aplastic anemia (DrugBank DB00033). Therapeutic targeting of this collective set of antigens works by inducing rapid and profound lymphopenia through complement-mediated lysis and apoptosis. This mechanism is highly effective for induction therapy in solid organ transplantation and for the treatment of steroid-resistant rejection. However, the broad targeting of immune cells also leads to significant safety concerns, including cytokine release syndrome and increased susceptibility to opportunistic infections (StatPearls NBK538224).

Other names

T-cell surface antigensLymphocyte-specific antigensThymocyte antigensT-lymphocyte antigens

Depletion of circulating T-lymphocytes through complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and opsonization followed by phagocytosis in the reticuloendothelial system (StatPearls NBK538224). It also induces apoptosis and modulates cell surface receptors involved in T-cell activation and leukocyte adhesion (DrugBank DB00033).