The WT.5 monoclonal antibody specifically recognizes the alpha subunit of LFA-1 (αLβ2 integrin, CD11a/CD18), a heterodimeric surface glycoprotein which is found on the majority of leukocytes, but not on peritoneal macrophages or peritoneal mast cells. LFA-1 mediates a variety of heterotypic and homotypic intercellular adhesions through interaction with ICAM-1 (CD54) and ICAM-2 (CD102). WT.1 mAb recognizes both the activated and unactivated forms of LFA-1. It inhibits the binding of LFA-1 to ICAM-1 in several in vitro assays, including binding of Concanavalin A-stimulated lymphocytes (Con A blasts) to purified ICAM-1 and Mg2+-dependent aggregation of concanavalin A-stimulated blasts. It has also been reported to inhibit leukocyte infiltration in several in vivo models of inflammation.
The antibody was conjugated to BD Horizon BUV615 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 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).