The 1G1 monoclonal antibody specifically binds to CD194, also known as the human CC Chemokine Receptor type 4 (CCR4). CCR4 is expressed on activated Th2 cells, regulatory T cells, activated NK cells, basophils, monocytes and platelets. CCR4 is a seven-transmembrane, G-protein-coupled receptor, and is the specific receptor for CC chemokines, CCL22/MDC/Macrophage-Derived Chemokine and CCL17/TARC/Thymus and Activation-Regulated Chemokine. It has been reported that CCR4 mRNA is expressed mainly in the thymus and spleen. The human CCR4 gene has been mapped to chromosome 3p24. The purified form of this antibody has been reported not to be a neutralizing antibody. The immunogen used to generate the 1G1 hybridoma has been reported to be human CCR4 transfected L1.2 mouse lymphoma cells.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.