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.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.