The OX-34 antibody reacts with CD2 (LFA-2), a member of the immunoglobulin superfamily. In the rat, CD2 is expressed on thymocytes, T lymphocytes in spleen and lymph node, dendritic epidermal T cells, splenic macrophages, and NK cells, but not on B cells, most intestinal intraepithelial lymphocytes, or peritoneal and liver macrophages. CD2 can associate with the T-cell receptor complex, and it may function in both intercellular adhesion and signal transduction. In the rat, CD48 and CD59 have been identified as ligands for CD2. OX-34 mAb binds to the extracellular portion of CD2, and it blocks the binding of CD2 to CD48. While OX-34 antibody does not activate T cells, it partially blocks activation by immobilized mAbs to CD3 (clone G4.18) and αβ T-cell receptor (clone R73), and it partially inhibits allogeneic mixed lymphocyte reactions. Moreover, in vivo administration of OX-34 antibody depletes peripheral T cells and prevents allograft rejection.
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.