A High Frequency of Peripheral Blood IL-22+CD4+ T Cells in Patients With New Onset Type 2 Diabetes Mellitus

Abstract

Background: This study is aimed at investigating the frequency of different functional IL-22+CD4+ T cells in Chinese patients with type 2 diabetes mellitus (T2DM). Methods: The frequency of circulating IFN-γ+IL-17-IL-22-CD4+ (Th1), IFN-γ-IL-17A+IL-22-CD4+ (Th17), and IFN-γ-IL-17A-IL-22+CD4+ (Th22), and other subsets of IL-22+CD4+ T cells in 31 patients with new onset T2DM and 16 healthy controls was characterized by flow cytometry. The levels of serum IL-22, IL-17, IFN-γ, insulin C-peptide, hemoglobin A1c (HbA1c), fasting plasma glucose, and insulin were examined. Results: The frequency of Th1, Th17, Th22, IFN-γ+IL-17-IL-22+, and IFN-γ-IL-17+IL-22+ CD4+ T cells and the concentrations of IL-22, but not IL-17 and IFNγ, in the patients were significantly higher than controls. The percentages of Th22 cells were correlated positively with the frequency of IFN-γ-IL-17+IL-22+CD4+ T cells, the values of body mass index (BMI) and homeostatic model assessment insulin resistance (HOMA-IR), and the levels of serum IL-22 in those patients. Conclusion: Our data suggest that IL-22+CD4+ T cells may contribute to the early process of T2DM.