The 7D3 monoclonal antibody specifically binds to T cell immunoglobulin mucin 3 (TIM-3) which is also known as, CD366, or T-cell immunoglobulin and mucin domain-containing protein 3 (TIMD-3/TIMD3). CD366 is encoded by the HAVCR2 gene (Hepatitis A virus cellular receptor 2). CD366 is a type I transmembrane glycoprotein and belongs to the human TIM family (along with TIM-1 and TIM-4) within the immunoglobulin superfamily. CD366 is expressed on Th1, Tc1, Th17, Treg, NK T, and NK cells. CD366 is also expressed on dendritic cells, mast cells, monocytes, and macrophages. It is not expressed by Th2 and B cells. CD366 helps maintain peripheral immune tolerance and homeostasis. CD366 regulates macrophage activation and is a negative regulator of Th1 cell function. Crosslinking of cell surface CD366 by binding to Galectin-9 and/or phosphatidylserine appears to play an important role in either positively or negatively regulating leucocyte functions, such as cytokine production or the phagocytosis of apoptotic cells. CD366 may also be useful as an AML stem cell surface marker because it appears to be more highly expressed by AML leukemia stem cells than by normal bone marrow hematopoietic stem 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).