The immunotoxic impacts of mercury during early life is poorly understood. We investigated the associations between gestational mercury exposure and frequency of cord blood T cells as well as placental gene expression. Frequency of natural Treg cells was positively associated with prenatal and postpartum mercury toenail concentrations. Frequency of NKT and activated naïve Th cells was positively associated with prenatal toenail mercury concentrations and number of maternal silver-mercury dental amalgams, respectively. Placental gene expression analyses revealed distinct gene signatures associated with mercury exposure. Decreased placental expression of a histone demethylase, KDM4DL, was associated with both higher prenatal and postpartum maternal toenail mercury levels among male infants and remained statistically significant after adjustment for fish and seafood consumption. The results suggest that gestational exposure to mercury concentrations contribute to alterations in both T cells and gene expression in placenta at birth. These alterations may inform mechanisms of mercury immunotoxicity.

人们对汞在生命早期的免疫毒性影响知之甚少。我们研究了妊娠期汞暴露与脐带血 T 细胞频率以及胎盘基因表达之间的关联。天然 Treg 细胞的频率与产前和产后趾甲汞浓度呈正相关。NKT 和活化的幼稚 Th 细胞的频率分别与产前趾甲汞浓度和母体银汞牙科汞合金的数量呈正相关。胎盘基因表达分析揭示了与汞暴露相关的独特基因特征。组蛋白去甲基化酶 KDM4DL 的胎盘表达减少与男婴产前和产后母体脚趾甲汞水平较高有关，并且在调整鱼类和海鲜消费后仍然具有统计学意义。结果表明，妊娠期接触汞浓度会导致出生时胎盘中 T 细胞和基因表达的变化。这些改变可能会揭示汞免疫毒性的机制。