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 BUV661 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 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).