The 159227 monoclonal antibody specifically recognizes MHC class I polypeptide-related sequence A (MICA) which is also known as MIC-A, MHC class I chain-related protein A, or stress inducible class I homolog. This ~70 kDa single-pass type I transmembrane glycoprotein is encoded by MICA (major histocompatibility complex class I chain-related gene A) which is a highly polymorphic gene. MICA is very homologous to another protein, MICB. Both MICA and MICB are homologous to major histocompatibility complex (MHC) class I molecules although they lack association with β2 microglobulin. MICA and MICB each contain three extracellular Ig domains but have no capacity to bind peptides. MICA is expressed on some gut epithelial cells. Its expression by other epithelial cells and cell types, including fibroblasts and endothelial cells, is induced by stress, eg, stress caused by bacterial and viral infections, autoimmunity, transplantation rejection, or cellular transformation. MICA and MICB are ligands for NKG2D (CD314), an activating receptor expressed by natural killer (NK) cells, γδ T cells, CD8+ αβ T cells, and some CD4+ αβ 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).