The H194-112 monoclonal antibody specifically binds to CD26, which is also known as, Thymocyte-activating molecule (THAM), or dipeptidyl peptidase IV (DPP IV, Dpp4). CD26 is a ~220- kDa dimer formed of identical type-II transmembrane core polypeptides which undergo variable post-translational modifications. It is a multi-functional molecule with both ectopeptidase and signal-transducing activities. Studies with specific DPP IV inhibitors suggest that the enzymatic activity is involved in the mediation of T-cell activation events. The expression of CD26 is developmentally regulated in the thymus. Resting lymphoid cells of the bone marrow and peripheral B and T lymphocytes express low levels of CD26; bone-marrow and peritoneal myeloid cells do not. CD26 is also found on epithelial cells in the kidney, liver, small intestine, and lung. Cross-linked H194-112 mAb induces proliferation of immature and mature thymocytes in the presence of either IL-1 plus IL-2 or PMA; addition of IL-2 or IL-4 to PMA further enhances the activation.
The antibody was conjugated to BD Horizon BUV395 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. With an Ex Max near 348 nm and an Em Max near 395 nm, BD Horizon BUV395 can be excited by the ultraviolet laser (355 nm) laser and detected with a 379/28 filter. This dye has been exclusively developed by BD Biosciences as an optimal dye for use on instruments equipped with the ultraviolet laser and has virtually no spillover into any other detector.