The 1F2 mAb reacts with Crry/p65, a cell-surface protein that blocks complement activation and C3 deposition by both the classical and alternative pathways. Based on nucleotide sequence identity, Crry/p65 is the genetic homologue of human CR1 (Complement Receptor 1). However, it has been proposed that Crry/p65 is the functional homologue of human MCP (Membrane Cofactor Protein) and/or DAF (Decay-Accelerating Factor), due to the similar functions these proteins share and the fact that Crry/p65 does not display CR1's complement-receptor activity. Crry/p65 is expressed in most organs, such as thymus, kidney, uterus, skin, lung, pancreas, heart, stomach, large and small intestine, and spleen. Platelets, brain, and muscle express low, but detectable levels of Crry/p65. In addition, Crry/p65 is expressed in J774 cells, bone marrow-derived macrophages, and thioglycollate-elicited peritoneal macrophages, as determined by RT-PCR. Crry is crucial in the regulation of complement activation during early mouse embryonic development and essential in fetomaternal tolerance. The 1F2 mAb partially blocks Crry/p65-mediated complement protection in vitro.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).