Alias: GITRL, TNFSF18, Tumor necrosis factor ligand superfamily member 18
GITRL is a type II transmembrane protein of the TNF superfamily and is expressed by endothelial cells and peripheral blood monocytes. GITRL binds to GITR/AITR, belonging to the Glucocorticoid-Induced TNFR family gene, also known as TNFRSF18. In naïve mice, GITR is expressed predominantly by CD4+CD25+ T regulatory cells (TReg) and by CD25+ CD4+ CD8- thymocytes. Stimulation with GITRL abrogates TReg cell-mediated suppression. The removal of GITR-expressing TReg cells or the administration of GITR antibody (DTA-1) resulted in organ specific autoimmune disease. Interaction of GITR, expressed by CD4+CD25+ TReg cells, with GITRL is important for cross-talk between T lymphocytes and endothelial cells.