The MIH37 monoclonal antibody specifically recognizes Programmed cell death 1 ligand 2 (PD-L2) which is also known as CD273 and Butyrophilin B7-DC (B7-DC). This regulatory molecule is a 42-kDa type I membrane glycoprotein encoded by Pdcd1lg2 which belongs to the B7 family of the Ig superfamily. CD273 (PD-L2) is comprised of an extracellular region with an N-terminal IgV-like domain followed by an IgC2-type domain, a transmembrane sequence, and a cytoplasmic tail. Although not detected on resting leucocytes, its expression is upregulated upon activation of macrophages and dendritic cells (DC) by a variety of stimulatory factors including IL-4, IL-13, or GM-CSF. CD273 (PD-L2) serves as a ligand for the coinhibitory receptor, CD279 (PD-1), a receptor that likewise binds to the CD274 (PD-L1) ligand. CD273 (PD-L2) also binds to Repulsive guidance molecule b (RGMb) that is expressed by T cells, macrophages, neutrophils, and DC. RGMb may associate with other receptors that transduce costimulatory or coinhibitory signals. The MIH37 antibody reportedly blocks the binding of CD273 (PB-L2) to its receptors, CD279 (PD-1) or RGMb and can inhibit antigen-specific T cell responses and hapten-induced contact hypersensitivity reactions. The TY25 monoclonal antibody reportedly binds with lower affinity near or at the same mouse CD273 (PD-L2) epitope recognized by the MIH37 antibody.
The antibody was conjugated to BD Horizon™ BUV805 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 805 nm. BD Horizon Brilliant BUV805 can be excited by the ultraviolet laser (355 nm) and detected with a 820/60 filter and a 770LP.