Peripheral Th17/Treg imbalance in patients with atherosclerotic cerebral infarction.

OBJECTIVE CD4(+)CD25(+) regulatory T (Treg) cells and Th17 cells play important roles in peripheral immunity. Oxidized low-density lipoprotein (ox-LDL) is an instrumental factor in atherogenesis. However, the changes of Th17/Treg cells in patients with acute cerebral Infarction (ACI) and impact on Th17/Treg by ox-LDL are not clear. Here, we examined the balance of Th17/Treg in ACI patients and the effect of ox-LDL on this balance. MATERIALS AND METHODS The frequencies of Th17 and Treg cells, key transcription factors and relevant cytokines were examined in patients with ACI, Transient ischemic attack (TIA) and controls. The correlations of cytokines, inflammatory biomarkers and ox-LDL in serum to Th17/Treg frequency, and the effects of ox-LDL on Th17/Treg cells in vitro were analyzed. RESULTS ACI patients have shown a significant increase of Th17 frequency, RORγt expression and Th17 related cytokines (IL-17 and IL-6 ) levels, and a clear decline of Treg frequency, Foxp3 expression, suppressive function and regulatory cytokines (IL-10 and TGF-β1) levels. Furthermore, TIA patients also have notable variation as compared to control group. Serum ox-LDL and inflammatory biomarkers were positively correlated with the frequency of Th17 cells and negatively correlated with the frequency of Treg cells. Treg and Th17 cells from ACI patients were significantly susceptible to ox-LDL-mediated alterations in vitro. CONCLUSIONS Th17/Treg cells were imbalanced in ACI patients, and ox-LDL may contribute to this imbalance and lead to the occurrence of ACI suggesting their pathogenetic role in ACI.