The 1C3 (AICD58.6) monoclonal antibody specifically binds to CD58. CD58 is a a 60-70 kDa glycoprotein member of the immunoglobulin superfamily. CD58, also referred to as the lymphocyte function-associated antigen-3 (LFA-3), has a wide tissue distribution, being expressed on both hematopoietic and non-hematopoietic cells, including endothelial cells and fibroblasts. There are two isoforms of CD58: a glycosylphosphatidylinositol (GPI)-linked form and a transmembrane form. Both isoforms may be expressed on the same cell type. Erythrocytes, however, only express the GPI-linked isoform. CD58 interacts with CD2 during cell adhesion. This binding can enhance antigen-specific T-cell activation. This interaction can also play a role in cell-mediated cytotoxicity.
The antibody was conjugated to BD Horizon™ BUV661 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.