Conclusions
TLR4 is stimulated in thymoma, causing an increase of Th17 cells and a decrease of Treg cells, namely an imbalance of Th17/Treg cells, resulting in MG.
Methods
We collect thymoma samples from 54 patients with or without MG, detecting the expression level of TLR4, MyD88, and NF-κB in thymoma tissues. Next, we established an in vitro experiment of coculturing thymoma cells with CD4+ T cells and detected the differentiation of Th17 cells and Treg cells and their marker protein, retinoid-related orphan receptor gamma t (RORγt) and forkhead transcription factor 3 (Foxp3).
Objective
Thymus is an immune organ in which pathological changes may cause autoimmune diseases, including myasthenia gravis (MG). Recent studies have focused on Toll-like receptor 4 (TLR4) signaling as the cause of such changes. In our previous study, an imbalance of T helper 17 (Th17) cells and T regulatory (Treg) cells was found in MG thymoma. These
Results
We found TLR4, MyD88, and NF-κB expressed more in MG thymoma compared with simple thymoma. After the transwell coculturing, we observed an imbalance of Th17/Treg cells after TLR4 stimulation. Conclusions: TLR4 is stimulated in thymoma, causing an increase of Th17 cells and a decrease of Treg cells, namely an imbalance of Th17/Treg cells, resulting in MG.