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A pilot study comparing T-regulatory cell function among healthy children in different areas of Gansu, China
Panhong Gou1, Xiaoru Chang1, Zhonghui Ye1
1Department of Toxicology, School of Public Health, Lanzhou University, No 199 Donggang West Road, Lanzhou, 730000, China.
Insights
High polycyclic aromatic hydrocarbon (PAH) air pollution in China is linked to impaired regulatory T (Treg) cell function in children. Gene expression of key Treg markers like Foxp3 was significantly lower in children from high-PAH areas, suggesting immune system dysfunction.
Area of Science:
- Environmental Health
- Immunology
- Toxicology
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants linked to immune system dysfunction.
- Previous research indicated PAHs impair regulatory T (Treg) cell function in children exposed to moderate pollution levels.
- The molecular mechanisms underlying PAH-induced Treg cell impairment require further elucidation, especially in regions with high pollution.
Purpose of the Study:
- To investigate the impact of high ambient air pollution, specifically PAHs, on Treg cell function in children in Gansu, China.
- To explore potential molecular mechanisms, including gene expression of Foxp3, TGF-β, and IL35, associated with PAH exposure and Treg cell function.
- To compare immunological markers between children from Lanzhou and Lintao, Gansu, representing different levels of PAH exposure.
Main Methods:
- Air pollution levels, including total PAHs and PM2.5, were measured in Lanzhou and Lintao, Gansu Province.
- Healthy children from both cities were recruited, and demographic data were collected.
- Peripheral blood samples were analyzed for Treg cell percentage (flow cytometry) and gene expression of Foxp3, TGF-β, and IL35 (RT-PCR).
Main Results:
- Lintao exhibited significantly higher PAH concentrations (707 ng/m³) compared to Lanzhou (326 ng/m³), while PM2.5 levels were comparable.
- Children in Lintao showed significantly lower gene expression of Foxp3, IL35, and TGF-β compared to those in Lanzhou.
- No significant difference was found in the percentage of Treg cells among CD4+ T cells between the two cities.
Conclusions:
- Higher ambient PAH exposure in Lintao, China, is associated with reduced gene expression of key Treg cell markers (Foxp3, IL35, TGF-β) in children.
- These findings suggest a potential impairment of Treg cell function, contributing to PAH-induced immunological dysfunctions.
- Further research is warranted to fully understand the mechanisms and long-term health implications of PAH exposure on the pediatric immune system.
Abstract:
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.
