Gestational Zinc Deficiency Impairs Humoral and Cellular Immune Responses to Hepatitis B Vaccination in Offspring Mice

BACKGROUND Gestational zinc deficiency has been confirmed to impair the infant immune function. However, knowledge about effects of maternal mild zinc deficiency during pregnancy on hepatitis B vaccine responsiveness in offspring is limited. In this report, we aimed to examine how maternal zinc deficiency during pregnancy influences humoral and cellular immune responses to hepatitis B vaccination in offspring of BALB/c mice. METHODOLOGY/PRINCIPAL FINDINGS From day 1 of pregnancy upon delivery, maternal mice were given a standard diet (30 mg/kg/day zinc), zinc deficient diet (8 mg/kg/day zinc), or combination of zinc deficient diet (8 mg/kg/day zinc in the first 2 weeks of gestation) and zinc supplement diet (150 mg/kg/day zinc for the last week of pregnancy), respectively. Newborn pups of these maternal mice were immunized with hepatitis B vaccine at postnatal weeks 0, 2 and 4. Then, splenocytes and blood samples from the offspring mice were harvested for detection of serum zinc concentrations, humoral and cell-mediated immune responses, expression of cytokines using ELISA, CCK-8 and flow cytometric analysis. Results from the present study demonstrated that gestational zinc deficiency inhibited antibody responses, and decreased the proliferative capacity of T cells in offsprings immunized with hepatitis B vaccine. Additionally, HBsAg-specific cytokines analysis revealed that gestational zinc deficiency could inhibit secretion of IFN-γ from splenocytes, and decrease IFN-γ expression of CD4(+) and CD8(+) T cells. CONCLUSIONS/SIGNIFICANCE Gestational zinc deficiency can weaken the humoral and cell-mediated immune responses to hepatitis B vaccine via decreasing B cell counts and hepatitis B virus-specific immunoglobulin G production, as well as reducing T cell proliferation, CD4(+)/CD8(+) T cell ratio, and Th1-type immune responses.