The WTH1 monoclonal antibody specifically binds to rat CD1d and crossreacts with mouse CD1d (with stronger reactivity against mouse CD1d1 than CD1d2). CD1d is a type I transmembrane glycoprotein that is noncovalently associated with β2-microglobulin. CD1d is expressed on various cell types including subsets of thymocytes, T cells, B cells, monocytes, macrophages, dendritic cells, endothelial cells and epithelial cells. Although structurally similar to MHC Class I antigens, CD1d molecules are rather non-polymorphic and serve to present non-peptide antigens such as endogenous or microbial glycolipids to T lymphocytes (NKT cells). The WTH2 monoclonal antibody reportedly binds to a non-overlapping epitope on rat CD1d and also crossreacts with mouse CD1d when compared with WTH1. Both WTH1 and WTH2 reportedly interfere with antigen recognition by CD1d-restricted T 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.