The GAP.A3 monoclonal antibody specifically recognizes the polymorphic HLA class I histocompatibility antigen, A-3 alpha chain (HLA-A3). This ~44 kDa human major histocompatibility complex (MHC) class I molecule noncovalently associates with the ~12 kDa monomorphic β2 microglobulin. Two major subtypes are encoded by HLA-A3, HLA-A3.1 and HLA-A3.2. HLA-A3 gene expression is more commonly detected in individuals from Europe and southern India. HLA-A3 is expressed on nearly all nucleated cells of HLA-A3-positive individuals. HLA-A3 functions in the presentation of antigens to CD8-positive T cells which may lead to the generation of HLA-A3-restricted cytotoxic T cells and memory T cells. When complexed with certain antigens, HLA-A3 can also bind to killer cell immunoglobulin-like receptors (KIR), such as KIR3DL2, and might regulate NK cell function.
Note: Since HLA-A3 expression varies between human populations, clone GAP.A3 staining can be donor-dependent. Based on in-house testing and current literature, individuals of European or Southern Indian descent more frequently express HLA-A3 than those of Asian descent. Data may differ between donors due to geographical variations of HLA-A3 expression.
The antibody was conjugated to BD Horizon™ BUV496 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 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.