Prenatal HgCl2 exposure in BALB/c mice: gender-specific effects on the ontogeny of the immune system

Because mercury is highly toxic to developing organisms, we tested the hypothesis that prenatal exposure to HgCl2 can induce persistent immune dysfunction. Pregnant BALB/c mice were administrated every other day, for 11 days with HgCl2 (200 μg/kg). Their offspring were studied at PND10, 14, 21, and 60. Lymph nodes (LN), spleens, and thymus were harvested and proliferation and cytokine production were studied in vitro. We report that prenatal HgCl2 exposure exerts organ-specific effects on cell number, proliferation, and cytokine production in pre-weaning pups. At adulthood (PND60), effects of prenatal HgCl2 exposure were still observed, but expressed differently in females and males. In adult females, an inhibitory effect was observed on cytokine production by thymocytes, LN cells, and splenocytes. In males, a stimulatory effect was observed. Overall, we conclude that in vivo exposures to low doses of HgCl2 can induce persistent sex-specific immunotoxic effects, observable in adulthood.