The 87G monoclonal antibody specifically recognizes Human Leukocyte Antigen G (HLA-G) which is encoded by HLA-G (major histocompatibility complex, class I, G). HLA-G is a nonclassical Major Histocompatibility Complex class I (MHC-Ib) molecule that is structurally related to the classical MHC class Ia antigens (HLA-A, -B, -C). Several HLA-G isoforms have been described including transmembrane HLA-G1, -G2, -G3, -G4 and soluble HLA-G5, -G6, and -G7. The 87G monoclonal antibody reportedly recognizes a conformationally-dependent epitope on the heterodimeric transmembrane HLA-G1 and soluble HLA-G7 isoforms that consist of an HLA-G alpha chain and β2-microglobulin (β2m). HLA-G1 is variably expressed on placental trophoblast cells, thymic epithelial cells, activated monocytes, macrophages, dendritic cells, and tumor cells. Heterodimeric HLA-G shows limited variation and binds a limited variety of self-peptides derived from intracellular proteins including histones and ribosomal proteins. This molecule binds to inhibitory receptors such as CD85d, CD85j, and CD158d that are differentially expressed by NK cells, T cells, monocytes, dendritic cells, and B cells. This interaction exerts suppressive regulation of immune responses and is thought to help safeguard maternal tolerance of the fetus during pregnancy. The 4H84 monoclonal antibody that reportedly recognizes denatured forms of HLA-G1 and HLA-G2 has also been described.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.