IL-10-Producing CD1dhiCD5+ Regulatory B Cells May Play a Critical Role in Modulating Immune Homeostasis in Silicosis Patients

Ying Chen; Chao Li; Yiping Lu; Huiying Zhuang; Weijia Gu; Bo Liu; Fangwei Liu; Jinkai Sun; Bo Yan; Dong Weng; Jie Chen

doi:10.3389/fimmu.2017.00110

IL-10-Producing CD1d^hiCD5⁺ Regulatory B Cells May Play a Critical Role in Modulating Immune Homeostasis in Silicosis Patients

Front Immunol. 2017 Feb 13:8:110. doi: 10.3389/fimmu.2017.00110. eCollection 2017.

Authors

Ying Chen¹, Chao Li¹, Yiping Lu¹, Huiying Zhuang¹, Weijia Gu¹, Bo Liu¹, Fangwei Liu¹, Jinkai Sun², Bo Yan², Dong Weng³, Jie Chen¹

Affiliations

¹ Division of Pneumoconiosis, School of Public Health, China Medical University , Shenyang , China.
² Department of Respiratory Medicine, Shenyang No. 9 Hospital , Shenyang , China.
³ Division of Pneumoconiosis, School of Public Health, China Medical University, Shenyang, China; Department of Respiratory Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.

Abstract

Silicosis is characterized by chronic lung inflammation and fibrosis, which are extremely harmful to human health. The pathogenesis of silicosis involves uncontrolled immune processes. Evidence supports that regulatory B cells (Bregs) produce negative regulatory cytokines, such as IL-10, which can negatively regulate immune responses in inflammation and autoimmune diseases. Our previous study found that IL-10-producing B cells were involved in the development of silica-induced lung inflammation and fibrosis of mice. However, little is known about the role of Bregs in silicosis patients (SP). In this study, we found that serum concentrations of IL-10 were significantly increased in SP by using protein array screening. We further determined that the frequency of IL-10-producing CD1d^hiCD5⁺ Bregs, not IL-10-producing non-B lymphocytes, was significantly higher in SP compared to subjects under surveillance (SS) and healthy workers (HW) by flow cytometry. We also found that regulatory T cells (Tregs) and Th2 cytokines (IL-4, IL-5, and IL-13) were significantly increased in SP. Th1 cytokines (IFN-γ, IL-2, and IL-12) and inflammatory cytokines (IL-1β, IL-6, and TNF-α) were not significantly different between SP, SS, and HW. Our study indicated that IL-10-producing CD1d^hiCD5⁺ Bregs might maintain Tregs and regulate Th1/Th2 polarization in SP, suggesting that IL-10-producing Bregs may play a critical role in modulating immune homeostasis in SP.

Keywords: IL-10; Th1/Th2 polarization; immune homeostasis; regulatory B cells; regulatory T cells; silicosis patients.