The 2F10 monoclonal antibody specifically recognizes exon v6-containing isoforms of the CD44 adhesion receptor (CD44v6). CD44 is a widely-expressed, 85-250 kDa type I transmembrane glycoprotein that regulates cellular adhesion, growth, and migration and is involved in cell-cell interactions. CD44 is a member of the hyaladherin family of hyaluronan-binding proteins. It serves as a multifunctional receptor for hyaluronic acid and other ligands including collagens, fibronectin, matrix metalloproteinases, and osteopontin. The standard form of CD44 (CD44s) contains an extracellular region with a hyaluronan-binding link domain and a stem region devoid of variable exon sequences that are followed by a transmembrane domain and a cytoplasmic tail. The cytoplasmic region is linked to the cytoskeleton and may be involved in signaling interactions. Alternative splicing of CD44 gene transcripts results in the differential inclusion of 10 variant exons (v1-10) within the stem region, either individually or in multiple combinations. This results in a large number of variant CD44 (CD44v) isoforms with different cell surface expression levels and functions. CD44 isoforms containing exon v6 (CD44v6) are variably expressed on epithelial cells, monocytes, macrophages, dendritic cells, and Langerhans cells. It is expressed on certain tumor cells and on cancer stem cells (CSCs) and is implicated in tumor cell metastasis. In addition to playing roles in cellular adhesion and migration, CD44 isoforms with exon v6 sequences may serve as coreceptors for some growth factors and cytokines including hepatocyte growth factor (HGF) which is involved in driving c-Met signaling.
The antibody was conjugated to BD Horizon™ BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max at 421-nm, BD Horizon BV421 can be excited by the violet laser and detected in the standard Pacific Blue™ filter set (eg, 450/50-nm filter). BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific Blue conjugates.