The hC3aRZ8 monoclonal antibody specifically binds to the human C3a Receptor (C3aR). C3aR is a seven-transmembrane glycoprotein, G-protein-coupled receptor that is the specific receptor for C3a anaphylatoxin. The C3aR consists of 482 amino acids forming a single polypeptide chain that is encoded by the C3AR1 gene located on chromosome 12 (location 12p13.31). C3aR are expressed by eosinophils, basophils, neutrophils, dendritic cells, monocytes, macrophages, endothelial cells and some T cells. C3a is a bioactive cleavage product released from Complement Component 3 (C3) during complement activation. C3a plays a role in a variety of cellular immune responses as well as being a potent pro-inflammatory agent. In response to bound C3a, this receptor stimulates cellular responses including chemotaxis, granule enzyme release and superoxide anion production and causes increased vascular permeability. In vivo, C3a production can initiate, contribute to, or exacerbate the inflammatory reactions seen in gram-negative bacterial sepsis, trauma, ARDS, ischemic heart disease, post-dialysis syndrome, and several autoimmune diseases including rheumatoid arthritis, lupus erythematosus, and acute glomerulonephritis.
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).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.