Origin of Th17 Cells in Type 2 Diabetes-Potentiated Periodontal Disease

New strategies are critically needed to counter uncontrolled periodontal infection and inflammation in obesity-associated type 2 diabetes (T2D). However, mechanisms that explain the relationship between periodontitis (PD) and T2D remain poorly understood. Several lines of evidence indicate that destructive immune responses potentiate periodontitis (PD) in T2D. B cells are abundant in periodontal lesions, and our data show that B cells are required for PD in obese/insulin resistant but not lean/normoglycemic mice. In mice and in people, T2D-primed B cells supported Th17 cytokine profiles, but B cells had a modest effect on T-cell function in samples from normoglycemic individuals. Given the recently appreciated importance of Th17 cells in PD outside a T2D milieu, our data raise the possibility that B cells indirectly promote T2D-potentiated PD through support of Th17 cells, which in turn directly promote PD. Data herein thereby suggest unexpected mechanisms that explain the clinical observation that T2D potentiates PD.