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Li Q.,Anhui Medical University | Wang Y.,University of Sydney | Li H.,Anhui Medical University | Shen G.,Anhui Medical University | And 3 more authors.
Cellular Physiology and Biochemistry | Year: 2014

Background: CD4+CD25+ regulatory T (Treg) cells and T-helper 17 (Th17) cells play important roles in acute cerebral infarction (ACI). Our previous findings have suggested that oxidized low-density lipoprotein (Ox-LDL) could influence Treg/Th17 ratio in ACI patients. However, the mechanisms are still not clear. Methods and Results: We evaluated the effects of ox-LDL on Th17/Treg cell apoptosis and proliferation in vitro. Our results demonstrated that with increased ox-LDL concentrations, the frequency and suppressive function of Treg cells was decreased while the frequency of Th17 cells was elevated in control subjects. In addition, AnnexinV+ apoptotic rate, Fas/Fas ligand (FasL) expression, and Caspase-3 activity were escalated in Treg cells while were no significant changes in Th17 cells. Simultaneously, 5-Bromo-29-Deoxyuridine (BrdU) and 3-(4,5-Dimethylthiazol-2-yl)- 2,5-Diphenyl Tetrazolium Bromide (MTT) incorporation of Th17 cells was elevated accompanied by upregulated nuclear factor-κB (NF-κB) activity. However, Th17 proliferation was decreased when pre-incubated with Pyrrolidine dithiocarbamate (PDTC, inhibitor of NF-κB activation). Furthermore, there were significant changes induced by ox-LDL in Treg apoptosis, Fas/FasL/Caspase-3 expression of Treg cells, and Th17 proliferation, NF-κB activation of Th17 in ACI patients than in patients with transient ischemic attack (TIA) and control subjects (P<0.01, P<0.05 respectively). Conclusion: These data support that ox-LDL may influence the Th17/Treg balance by modulating Fasmediated Treg apoptosis and NF-κB-Associated Th17 proliferation. Ox-LDL also induced a more significant alteration of Treg and Th17 in ACI patients than in TIA and control groups, suggesting a novel role in the pathogenesis of ACI. © 2014 S. Karger AG, Basel. Source

Cheng M.,Anhui Medical University | Cheng M.,Anhui Provincial Key Laboratory of Tumor Immunotherapy and Nutrition Therapy | Qian L.,Anhui Medical University | Qian L.,Anhui Provincial Key Laboratory of Tumor Immunotherapy and Nutrition Therapy | And 10 more authors.
Cancer Research | Year: 2014

Commensal bacteria are crucial to maintain immune homeostasis in mucosal tissues and disturbances in their ecology can affect disease susceptibility. Here, we report evidence that commensal bacteria shape the efficiency of immune surveillance in mucosal tissues. Antibiotic-treated (Abt) mice were more susceptible to development of engrafted B16/F10 melanoma and Lewis lung carcinoma, exhibiting a shortened mean survival time with more numerous and larger tumor foci in the lungs. The defective antitumor response of Abt mice was independent of dehydration caused by antibiotics. Host defenses relied upon intact commensal bacteria with no class specificity. Mechanistic investigations revealed a defective induction of the γδT17 cell response in lungs of Abt mice; here, more aggressive tumor development was observed, possibly related to a reduction in IL6 and IL23 expression there. Adding normal gdT cells or supplementing IL17 restored the impaired immune surveillance phenotype in Abt mice. Overall, our results demonstrated the importance of commensal bacteria in supporting the host immune response against cancer, defined an important role for γδT17 responses in the mechanism, and suggested deleterious effects of antibiotic treatment on cancer susceptibility and progression. © 2014 American Association for Cancer Research. Source

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