A pilot study comparing T-regulatory cell function among healthy children in different areas of Gansu, China
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Immune system is critical to protecting human health from toxic substances. Our previously published research had found an important link between polycyclic aromatic hydrocarbons (PAHs) in ambient air and changes at the DNA level in immune cells that led to impaired function of regulatory T (Treg) cells in children living in California, USA. But molecular and cellular pathways of these changes remain unclear. The present study aims to explore whether exposure to PAHs leads to changes in Treg cells functions of children living in Gansu, China, where ambient air pollution levels are much higher than those in California, and to explore potential mechanisms of PAH-induced immunological dysfunctions. Air pollutions in Lanzhou and Lintao, Gansu Province, were measured from December 2015 to June 2016. Healthy children were recruited from both cities and enrolled in this pilot study. Demographic information was collected by questionnaires. Blood samples were collected. Peripheral blood Treg cells were analyzed for Treg cells percentage by flow cytometry. Gene expression of forkhead box transcription factor 3 (Foxp3), transforming growth factor-β (TGF-β), and interleukin 35 (IL35) were examined by reverse transcription-polymerase chain reaction (RT-PCR). The results indicated PAH concentration (as sum of 16 PAHs) in Lintao was over two times higher than that was in Lanzhou (707 vs. 326 ng/m3), whereas PM2.5 concentration was comparable in two cities (55.3 in Lintao vs. 65.7 μg/m3 in Lanzhou). Notably, we observed lower gene expressions for Foxp3 (P < 0.05), IL35 (P < 0.05), and TGF-β, in children living in Lintao, suggesting an impairment of Treg cells function potentially associated with higher PAH exposure in Lintao. However, no significant difference was observed in Treg cells % among CD4+ T cells between Lanzhou and Lintao groups.
KeywordsAir pollution Immune system Treg cells Immune system Cytokine
This study was supported by Chau Hoi Shuen Women in Science Program. The authors wish to thank the hospital staff for their assistance in blood sample collection and the children from both cities for their participation.
Sa Liu, Junling Wang, and S. Katharine Hammond conceived and designed the study. Panhong Gou, Zhonghui Ye, and Yueli Yao carried out the data collection. Panhong Gou, Xiaoru Chang, and Patton Khuu Nguyen conducted the labor test. Panhong Gou analyzed the data and developed the initial draft of the paper. All authors reviewed and provided input to the writing, editing, and finalization of the paper.
Compliance with ethical standards
Conflicts of interest
The authors declare that they have no conflict of interest.
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