The 232-5 monoclonal antibody specifically recognizes Butyrophilin 3 (BTN3), which is also known as CD277. BTN3 is comprised of three structurally related members, BTN3A1, BTN3A2, and BTN3A3. BTN3 molecules are transmembrane type 1 glycoproteins that belong to the Ig superfamily. The 232-5 antibody recognizes the variable region of the extracellular domains of BTN3 molecules. BTN3 molecules are differentially expressed by T, NKT, B, and NK cells, monocytes, macrophages, dendritic cells, as well as some stem cells and tumor cells. BTN3 expression is decreased upon lymphocyte activation. The extracellular domain of CD277 is structurally related to the B7 family of proteins that regulate T cell activation. A soluble form of the 232-5 antibody can serve as an agonist in BTN3-mediated regulation of anti-CD3 ± anti-CD28 antibody activated CD4+ or CD8+ T 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).