The MIH18 monoclonal antibody specifically binds to CD273 which is also known as the Programmed Death Ligand 2 (PD-L2) and B7-DC. CD273 is a type 1 transmembrane glycoprotein member of the B7 family and Ig superfamily. CD273 serves as a ligand for CD279, the Programmed Death 1 (PD-1) receptor. CD273 is expressed by dendritic cells, activated monocytes, medullary thymic epithelial cells, placental trophoblasts, and myocardial endothelium. CD273 can function as a coinhibitor of T cell functions by acting through CD279. Monoclonal antibodies that block the CD273 and CD279 interaction result in enhanced T cell proliferation and cytokine production. Thus, CD273 can play an important role in regulating T cell responses. Clone MIH18 is reportedly a blocking antibody.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.