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 Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor™ 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor™ 700.