Laboratory of Environmental Medicine and Developmental Toxicology, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, Guangdong, China.
Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, Guangdong, China.
Sci Total Environ. 2021 Apr 10;764:142806. doi: 10.1016/j.scitotenv.2020.142806. Epub 2020 Oct 8.
Immunoglobulin G (IgG) is the predominant component of the humoral immune system. Epidemiological studies have shown that lead (Pb) or cadmium (Cd) exposure is associated with changes in human IgG levels, and alteration of IgG subclass production can be induced by differential modulation of Th1 and Th2 cytokines caused by Pb or Cd exposure. However, no study has focused on the adverse effects of Pb and Cd co-exposure on IgG subclass production by regulating Th1/Th2 cytokines in children living in electronic waste (e-waste) areas. This study aims to analyze the associations among Pb and Cd in blood, Th1/Th2 cytokines, and IgG subclasses in serum from children. A total of 181 healthy, 2- to 7-year-old children were examined. Of them, 104 were from Guiyu (e-waste exposed group), and the rest were from Haojiang (reference group) in China. Pb and Cd levels in whole blood, cytokines, and IgG subclasses in serum were determined. Exposed children had higher levels of blood Pb and Cd, serum IgG1, IgG1 + IgG2, serum Th1 cytokine interferon-γ (IFN-γ) and lower levels of the Th2 cytokine interleukin (IL)-13. Increased blood Pb levels were positively associated with serum levels of IFN-γ, and negatively associated with serum levels of IL-13. Adjusted linear regression analysis showed that serum levels of IL-13 were negatively associated with serum levels of IgG1 and IgG1 + IgG2. Mediation models indicated that IL-13 had significant mediating effects on the relationships between blood Pb levels and serum IgG1, as well as between blood Pb levels and serum IgG1 + IgG2. Increased blood Cd levels were positively associated with serum levels of IgG1. Our results show heavy metal (particularly Pb) exposure may affect IgG subclass production by regulating Th1/Th2 cytokines in exposed children, thus providing new evidence for a relationship between humoral immune function and environmental exposure.
免疫球蛋白 G（IgG）是体液免疫系统的主要成分。流行病学研究表明，铅（Pb）或镉（Cd）暴露与人类 IgG 水平的变化有关，并且 Pb 或 Cd 暴露引起的 Th1 和 Th2 细胞因子的差异调节可诱导 IgG 亚类产生的改变。然而，尚无研究关注生活在电子废物（e-waste）地区的儿童中 Pb 和 Cd 共同暴露通过调节 Th1/Th2 细胞因子对 IgG 亚类产生的不良影响。本研究旨在分析儿童血液中的 Pb 和 Cd、Th1/Th2 细胞因子和血清 IgG 亚类之间的关联。共检查了 181 名健康的 2-7 岁儿童。其中，104 名来自贵屿（电子废物暴露组），其余来自中国濠江（参考组）。测定全血中的 Pb 和 Cd、血清中的细胞因子和 IgG 亚类。暴露组儿童的血 Pb 和 Cd 水平、血清 IgG1、IgG1+IgG2 水平较高，Th1 细胞因子干扰素-γ（IFN-γ）水平较低，Th2 细胞因子白细胞介素（IL）-13 水平较高。血 Pb 水平升高与血清 IFN-γ水平呈正相关，与血清 IL-13 水平呈负相关。调整后的线性回归分析表明，血清 IL-13 水平与血清 IgG1 和 IgG1+IgG2 水平呈负相关。中介模型表明，IL-13 对血 Pb 水平与血清 IgG1 以及血 Pb 水平与血清 IgG1+IgG2 之间的关系具有显著的中介作用。血 Cd 水平升高与血清 IgG1 水平呈正相关。我们的研究结果表明，重金属（尤其是 Pb）暴露可能通过调节 Th1/Th2 细胞因子影响 IgG 亚类的产生，从而为体液免疫功能与环境暴露之间的关系提供了新的证据。
