The MECA-89 antibody specifically recognizes the mucosal vascular addressin cell adhesion molecule (MAdCAM-1). In the fetus and neonate, MAdCAM-1 is the predominant vascular addressin on the high endothelial venules (HEV) of peripheral lymph nodes. In adult mice, MAdCAM-1 is preferentially expressed in mucosal lymphoid tissues and lamina propria; it is also expressed on sinus-lining cells in the spleen. MAdCAM-1 expression is upregulated on the HEV of peripheral lymph nodes in adult NOD mice and is involved in the development of diabetes and insulitis. Furthermore, there is evidence that IFN-γ can induce MAdCAM-1 expression in non-mucosal sites in adult mice. MAdCAM-1 is a predominant ligand for integrin α4β7, a lymphocyte mucosal homing receptor, and a facultative ligand for CD62L (L-selectin). MECA-89 mAb binds to the second domain of MAdCAM-1 and does not block MAdCAM-1-dependent binding in vitro. Source of the immunogen was endothelial cells from BALB/c mouse mesenteric and peripheral lymph nodes.
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).