The 5E8 monoclonal antibody specifically binds to human CCR3 which is also known as CD193. CCR3 is a G protein-linked, 7 transmembrane, chemokine receptor expressed on a variety of hematopoietic cells. Similar to CCR5 and CXCR4, CCR3 can be a co-receptor for HIV-1. It is primarily expressed by eosinophils and basophils during atopic conditions, dermatitis, allergic rhinitis, conjunctivitis and bronchial asthma. Chemokines including RANTES, Eotaxin, MCP-3, MIP1α have been reported to act as ligands for CCR3 and stimulate CCR3+ cells. Eotaxin stimulates Th2 cells expressing CCR3. Other studies describe HIV-1 specific T cell cytotoxicity can be mediated by RANTES and Eotaxin through CCR3. CCR3 expressed on dendritic cells may have a biological role on cell-cell interaction during antigen presentation. CCR3 has been clustered as CD193 in the HLDA VIIIth workshop.
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.