KLK5 induces shedding of DPP4 from circulatory Th17 cells in type 2 diabetes

Objective: Increasing plasma levels and activity of dipeptidyl peptidase-4 (DPP4 or CD26) are associated with rapid progression of metabolic syndrome to overt type 2 diabetes mellitus (T2DM). While DPP4 inhibitors are increasingly used as anti-hyperglycemic agents, the reason for the increase in plasma DPP4 activity in T2DM patients remains elusive. Methods: We looked into the source of plasma DPP4 activity in a cohort of 135 treatment naive nonobese (BMI