CD26: a key molecule in immune regulation and autoimmune diseases.

Abstract In this review, we focus on major aspects of the biology of CD26, a dipeptidyl peptidase IV (DPPIV)-containing surface glycoprotein with multiple functions. In particular, we discuss findings demonstrating that CD26/DPPIV has an essential role in immune regulation as a T cell activation molecule and a regulator of chemokine function. We also review recent studies that identify key cellular molecules that physically associate with CD26 and the potential consequences of their interaction, including those with clinically related implications. Furthermore, we present work suggesting a role for CD26 in the pathophysiology of immune-mediated disorders as well as autoimmune diseases. We present recent studies that investigate the potential role of CD26 as a molecular target for novel treatment modalities for immune-mediated diseases, with work involving the use of anti-CD26 monoclonal antibody, DPPIV inhibitors, and soluble CD26 molecules.