Cigarette smoke exposure promotes differentiation of CD4⁺ T cells toward Th17 cells by CD40–CD40L costimulatory pathway in mice

Abstract

Purpose

This study aimed to investigate the impact of cigarette smoke exposure upon CD40–CD40L ligation between bone marrow-derived dendritic cells (BMDCs)and CD4⁺T cells, and to examine the effects of cigarette smoke exposure upon differentiation of CD4⁺T cells toward Th17 cells through blockade of CD40-CD40L pathway in mice.

Methods

The study was processed in vivo and in vitro. In vivo, Th17 cells, CD40, interleukin (IL)-17A, and IL-27 in the lung tissues were quantified and compared between mice with and without cigarette smoke exposure. In vitro, Th17 cells, IL-17A, and IL-27 yielded by multiple cell cultivations in which BMDCs from mice with or without cigarette smoke exposure were fostered with CD4⁺ T cells from healthy mice spleens in the presence of antagonistic CD40 antibody and/or cigarette smoke extract (CSE) were quantified and compared. The flow cytometry was used to detect expressions of Th17 cells and CD40, and the liquid chip was used to detect levels of IL-17A and IL-27.

Results

Both in vivo exposed to cigarette smoke and in vitro to CSE, CD40 expressions noticeably escalated on the surfaces of BMDCs. The presence of Th17 cells, IL-17A, and IL-27 in the lung tissues prominently increased in mice exposed to cigarette smoke. The in vitro culture of CD4⁺ T cells and BMDCs significantly enhanced the differentiation of CD4⁺ T cells toward Th17 cells and secretions of IL-17A and IL-27 in the case that BMDCs were produced from mice exposed to cigarette smoke or the culture occurred in the presence of CSE. Usage of antagonistic CD40 antibody evidently reduced the number of Th17 cells, IL-17A, and IL-27 that increased due to cigarette smoke exposure.

Conclusion

The CD40–CD40L ligation is associated with the quantities of Th17 cells and relevant cytokines in the context of cigarette smoke exposure. Reducing the number of Th17 cells via the usage of antagonistic CD40 antibody can be an inspiration for pursuing a novel therapeutic target for immune inflammation in COPD.

Keywords:

• cigarette smoke extract
• BMDC
• CD4⁺IL-17⁺ T cell
• CD40–CD40L pathway
• IL-17A
• IL-27

Acknowledgments

This study was funded by grants from National Natural Science Foundation of China (grant number 81660007), Youth Foundation of Guangxi Medical University (grant number GXMUYSF-201614), and Talents Highland of Emergency and Medical Rescue of Guangxi Province in China (grant number GXJZ201514). YL and YS are the co-first authors.

Author contributions

XZ made substantial contributions to concept and design of this study, data interpretation, and critical modifications of some important intellectual contents. YL and YS equally made substantial contributions over drafting this article, data acquisition, and data interpretation. LK, GZ, and LZ were significantly involved in data acquisition and data analysis. JZ managed some important modifications over the content. JL substantially contributed to data analysis. All authors contributed toward data analysis, drafting and critically revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.