The G28-8 monoclonal antibody specifically recognizes RP105/Bgp95, a 95-105 kDa type I membrane protein consisting of extracellular leucine-rich repeats and a short cytoplasmic domain. It is expressed on mantle zone B cells, but weakly on germinal center B cells. RP105/Bgp95 is also expressed on peripheral blood monocytes, dendritic cells, and a subset of peripheral blood lymphocytes. The extracellular domain associates with a molecule called MD-1 to form a cell surface receptor complex RP105/Bgp95/MD- 1. This receptor belongs to the family of toll-like receptors (TLR). Studies show that RP105/Bgp95/MD-1, working in concert with TLR4, controls B cell recognition and signaling of lipopolysaccharide (LPS). Reports on functional studies show that G28-8 monoclonal antibody can induce a G0 to G1 cell cycle transition and was synergistic with PMA, anti-µ, or anti-CD40 in inducing proliferation of resting B cells.
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.