Peripheral blood CD4+ T cell populations by CD25 and Foxp3 expression as a potential biomarker: reflecting inflammatory activity in chronic obstructive pulmonary disease

Abstract

Background

The temporally dynamic changes of CD25 and Foxp3 expression in CD4+ T cells are initiated by T cell receptor (TCR) signals strength or frequency. There is a deficiency of peripheral markers for assessing COPD activity, and the current study was conducted to explore whether peripheral CD4+ T cell populations based on CD25 and Foxp3 expression could serve as an indicator for COPD inflammatory activity.

Methods

The distribution and phenotypic characteristics of CD4+CD25±Foxp3± T cells from peripheral blood in different populations were determined by flow cytometry. The model for the differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was explored in vitro.

Results

The frequencies of peripheral CD4+CD25+Foxp3− T cells and CD4+CD25+Foxp3+ T cells were increased in AECOPD patients, whereas the frequency of CD4+CD25−Foxp3+ T cells was increased in SCOPD patients without receiving systemic treatment. Phenotypic analysis revealed that CD4+CD25+Foxp3− T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25−Foxp3+ T cells had received antigenic stimulation and resembled central memory or effector memory T cells. The differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was dictated by TCR signals. The paired study indicated that the frequencies of CD4+CD25+Foxp3− T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25− Foxp3+ T cells were decreased while the frequency of CD4+CD25−Foxp3− T cells were increased in the same patients from AECOPD to convalescence.

Conclusions

Collectively, we propose that the dynamic changes of CD4+ T cell populations by CD25 and Foxp3 expression could function as potential biomarkers for reflecting inflammatory activity in COPD.

Keywords:

• COPD
• CD4+ T cell subsets
• inflammation
• peripheral biomarkers

Acknowledgments

The authors thank Yi-Ting Xu, Zhen Yu and Pan-Pan Chang for their technical assistance. We thank Jointown Caritas Fund of Hubei Red Cross Foundation for their support of our research. This work was supported by the National Nature Science Foundation of China (No. 81570032; No. 81370146) and the Scientific Research Project of Health and Family Planning Commission of Hubei province (WJ2017M097). This work was also funded by Jointown Caritas Fund of Hubei Red Cross Foundation.

Disclosure

The authors report no conflicts of interest in relation to this work.