Masuda [22] demonstrated that there was a significant correlation between the RORγt mRNA levels and the Th1/Th2 ratio in CD4+ cells, but they did not find any significant correlation between the frequency of Th17 cells (%) in the peripheral lymphocytes and the clinical QMG scores (%). In our study, a further regression analysis Metabolism inhibition showed that
the frequency of Th17 cells (%) and the QMG score had a significant positive correlation in MG patients with TM. However, we did not find any similar correlation in TH group or NT group. In this regard, these results indicated that the frequency of Th17 cells (%) was correlated with MG severity only in TM. The balance of Th17 cells and Treg cells was suggested to be responsible for many autoimmune diseases including primary biliary cirrhosis, allergic asthma and systemic lupus erythematosus [32–34], and many studies have also
suggested an important role of Treg in the pathogenesis of MG. Luther [10] found a marked decrease in the number of CD4+ CD25+ Treg cells in MG-associated TM, but no differences in the peripheral blood. In addition, Balandina [9] found a severe suppressive activity impairment of thymic CD4+ CD25− FoxP3+ Treg cells in patients with MG. In our previous study [35], we found that the Treg cell counts in TM accompanying MG were significantly lower than those in normal thymuses. Among the thymoma types, type B1 thymoma had the highest Foxp3+ nTreg count and standard values of Foxp3 mRNA. Further, in this study, we found that the proportion of CD4+ FoxP3+
Treg cells in the peripheral blood from TM group was significantly lower than those from TH group, NT group and FK228 HC group. Thus, our results suggest that the percentage of CD4+ FoxP3+ Treg cells both in the peripheral lymphocytes and in the thymus also contributes to the pathogenesis of MG with TM. However, the role of Th17 cells in TM in the pathogenesis and progression of MG needs further study. In conclusion, Th17 cells and Treg cells play a key role in immune regulation, and the Th17/Treg imbalance in TM may result in the destruction of immune tolerance and Molecular motor induce autoimmune disorders, such as MG. Our results indicated that the transcriptional levels of IL-17 and numbers of Th17 cells increased significantly in patients with MG accompanying TM. In addition, we demonstrated a positive relationship between the frequency of Th17 cells (%) and the concentration of AChR antibodies in serum. The increased IL-17 levels in this circumstance may promote the autoreactivity of T cells as well as B cells, and the activated T and B cells may then influence the production of self-reactive antibodies and aggravate the disease. Our findings suggest that Th17 cells and their related cytokines are involved in the pathophysiological process of MG, especially in MG with TM. The underlining mechanisms, and the diagnostic value and therapeutic indication of Th17 cells and their related cytokines in MG need further evaluation.