The MD22 monoclonal antibody specifically recognizes CD64 which is also known as Fc-gamma receptor I (FcgR1) or FcγRI. CD64 is a ~72 kDa type I transmembrane glycoprotein that is encoded by FCGR1A (Fc fragment of IgG receptor Ia). CD64 functions as a high affinity receptor for human IgG. The CD64 antigen is expressed on monocytes, macrophages, at low levels on polymorphonuclear neutrophils (PMNs), and on a subpopulation of circulating dendritic cells. The CD64 antigen is an early granulomonocytic lineage marker on CD34+ hematopoietic progenitors. Expression of the CD64 antigen increases transiently in cases of sepsis. The CD64 antigen functions in both innate and adaptive immune responses, and mediates endocytosis, phagocytosis, antigen presentation, antibody-dependent cellular cytotoxicity, cytokine release, and superoxide generation. The CD64 antigen associates with the signal-transducing γ-chain homodimer of Fc receptors to form the functional high affinity FcγRI complex. Ligation of the CD64 antigen leads to the activation of the protein tyrosine kinases, hck and lyn.
The antibody was conjugated to BD Horizon™ BV510 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 405-nm and Em Max at 510-nm, BD Horizon BV510 can be excited by the violet laser and detected in the BD Horizon V500 (525/50-nm) filter set. BD Horizon BV510 conjugates are useful for the detection of dim markers off the violet laser.