The DTA-1 monoclonal antibody specifically binds to GITR [Glucocorticoid-induced Tumor necrosis factor (TNF) receptor family-Related], a 66-70-kDa homodimer glycoprotein that is a member of the TNF receptor superfamily and is also known as TNFRSF18 and CD357. As its name implies, GITR expression was first detected in T lymphocytes that had been treated with dexamethasone, a glucocorticoid. In normal naive mice, GITR is expressed at moderate levels on CD25-positive/CD4-positive/CD8a-negative thymocytes and on CD25-positive/CD4-positive/CD45RB-low splenocytes. It is also expressed at low levels on splenic CD25-negative/CD4-positive/CD45RB-low T lymphocytes, B lymphocytes, macrophages, and dendritic cells. Activation of T and B lymphocytes upregulates GITR expression. GITR is a costimulatory receptor that plays an important role in Regulatory T (Treg)-cell functions, and a GITR Ligand has been detected on B lymphocytes, macrophages, and dendritic cells. mAb DTA-1 abrogates suppression by Treg cells without affecting their proliferative response, while it is co-stimulatory for T lymphocytes that are not Treg cells.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).