The AFS98 monoclonal antibody specifically recognizes CD115 which is also known as Colony stimulating factor 1 Receptor (CSF-1R), Macrophage colony-stimulating factor 1 receptor (M-CSFR), or c-fms. This type I transmembrane glycoprotein is a receptor tyrosine kinase (RTK) that is encoded by Csf1r which belongs to the Ig superfamily. CD115 (CSF-1R) is comprised of an extracellular ligand-binding domain that is followed by a single transmembrane segment and a split intracellular tyrosine kinase domain. This receptor is expressed on monocytes, macrophages, dendritic cells, osteoclasts, and their precursors. Colony-stimulating factor 1 (CSF-1), also known as Macrophage colony-stimulating factor (M-CSF), binds to and signals through CD115 (CSF-1R) homodimers which undergo tyrosine autophosphorylation. The activated receptors transduce intracellular signals resulting in cytoskeletal reorganization and gene expression involved in the proliferation, differentiation, and survival of CSF-1-responding cells. Through CD115 (CSF-1R), CSF-1 regulates the release of proinflammatory cytokines and other mediators from macrophages and plays a role in the bone resorption activity of osteoclasts. Interleukin-34 (IL-34) is another ligand for CD115 (CSF-1R) that can induce similar, as well as, some different biological responses by target cells that express this receptor.
The antibody was conjugated to BD Horizon BUV737 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 737 nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 nm filter. Due to the excitation of the acceptor dye by the red laser line, there may be significant spillover into red laser detectors with filters in the 700-720 nm range.