Abstract: Abstract：Objective To assess whether mTOR was activated in peripheral T lymphocytes of acute coronary syndrome （ACS）patients and to investigate the relationship among mTOR，regulatory T cells and cytokins. Methods Patients with acute coronary syndrome (n=32) were selected in ACS group. Meanwhile, patients who complainted of chest pain but were proven to be normal in ECG and in coronary arteriography, were excluded as ACS patients but were diagnosed as Chest Pain Syndrome (CPS) and selected in CPS group (n=28). The expression levels of mTOR, phospho- p70S6KT389 (indicative of mTORC1 activity) and phospho-AKTS473(indicative of mTORC2 activity) were investigated in T cells, which were isolated from peripheral blood of patients in ACS group or CPS group, using Western blot. The proportion of CD4+CD25+Foxp3+Tregs over CD4+ cells were evaluated by FACS. And T cell subset related cytokines such as IFN-γ, IL-4, IL-17 and TGF-β1 were exam⁃ ined by ELISA. Then we investigated the relationship among mTOR，regulatory T cells and cytokins by Spearman analysis. Results mTOR and p-p70S6KT389 expression were significantly enhanced in ACS group as compared with those in patients from CPS group (P＜0.01). Higher levels of IFN-γ, IL-17 but lower level of TGF-β1 cytokines as well as decreased propor⁃ tion of Tregs were observed in ACS group than those in CPS group (P＜0.05). There was no significant difference in the level of IL-4 and p-AKTS473 between the two groups (P＞0.05). By correlation analysis, p-p70S6KT389 expression level positively correlated with IFN-γ, IL-17（rs=0.91,092，P＜0.01）and negatively correlated with Tregs and TGF-β1 （rs=-0.85,-0.80, re⁃ spectively, P＜0.01）. Conclusion mTORC1 pathway was activated in peripheral T lymphocytes of ACS patients, and Tregs insufficiency and cytokins imbalance both contribute to the activation of mTORC1 pathway and pathological process of ACS.

Key words: acute coronary syndrome, tacrolimus binding proteins；T-lymphocytes, regulatory；cytokines；mTOR