Wu, Xiu‐Zhi, Zhai, Kan, Yi, Feng‐Shuang, Wang, Zhen, Wang, Wen, Wang, Yao, Pei, Xue‐Bin, Shi, Xin‐Yu, Xu, Li‐Li, and Shi, Huan‐Zhong
The role of IL‐10 in malignant pleural effusion (MPE) remains unknown. By using murine MPE models, we observed that an increase in pleural IL‐10 was a significant predictor of increased risk of death. We noted that TH1‐ and TH17‐cell content in MPE was higher in IL‐10–/– mice than in WT mice, and IL‐10 deficiency promoted differentiation into TH1 but not into TH17 cells. A higher fraction of TH1 and TH17 cells in the MPE of IL‐10–/– mice expressed CXCR3 compared with WT mice. We also demonstrated that Lewis lung cancer and colon adenocarcinoma cells secreted large amounts of CXCL10, a ligand of CXCR3, which induced the migration of TH1 and TH17 cells into the MPE, and IFN‐γ could promote this signaling cascade. Furthermore, intrapleural injection of mice with CXCL10‐deficient tumor cells led to decreased TH1‐ and TH17‐cell content in MPE, increased MPE volume, and reduced survival of MPE‐bearing mice. Taken together, we demonstrated that IL‐10 deficiency promoted T‐cell differentiation into TH1 cells and upregulated the CXCR3‐CXCL10 signaling pathway that recruits TH1 and TH17 cells into MPE, ultimately resulting in decreased MPE formation and longer survival time of mice‐bearing MPE. IL‐10 promoted the development of malignant pleural effusion by suppressing the differentiation of naïve CD4+ T cells into TH1 cells and by suppressing the CXCR3‐CXCL10 signal that traffics TH1 and TH17 cells into the pleural space. [ABSTRACT FROM AUTHOR]