The OX-40 antibody reacts with the 50-kDa OX-40 Antigen (CD134), also known as OX-40 Receptor, on CD4+ T lymphocytes activated in vitro and in vivo. The antigen is a member of the NGFR/TNFR superfamily, which includes low-affinity nerve growth factor receptor, TNF receptors, the Fas antigen, CD137 (4-1BB), CD27, CD30, and CD40. CD134 supplies costimulatory signals for T-cell proliferation and effector functions. While OX-40 mAb is not mitogenic, it does augment some in vitro T-cell responses. It is also reported to block binding of OX-40 Ligand to OX-40 Antigen.
The antibody was conjugated to BD Horizon™ BUV496 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 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.