The L306.4 monoclonal antibody specifically recognizes CD58 which is also known as Lymphocyte function-associated antigen-3 (LFA-3) or Ag3. CD58 is a ~40 to 65 kDa cell-surface glycoprotein that belongs to the immunoglobulin superfamily. The CD58 antigen mediates cellular adhesion and participates in signal transduction when it binds to its ligand, the CD2 antigen. Cellular interactions regulated by the CD58/CD2 antigens are involved in the antigen-independent adhesion pathway and cytotoxic T lymphocyte (CTL) activity. The CD58 antigen has two isoforms. One isoform is anchored in the cell membrane by a glycophosphatidyl inositol tail, while the other is a type I transmembrane glycoprotein which has a transmembrane hydrophobic segment and a cytoplasmic segment composed of 12 amino acids. The CD58 antigen is widely distributed on cells of both hematopoietic and nonhematopoietic origin. The CD58 antigen is expressed on approximately 40% to 60% of peripheral blood lymphocytes, including CTL. It is also expressed on monocytes, granulocytes, B lymphoblastoid cell lines (such as JY and Daudi), platelets, vascular endothelium and smooth muscle, fibroblasts, and approximately 40% of bone marrow cells.
The antibody was conjugated to BD Horizon™ BV711 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.