The Effect of in Utero Exposure to Hexachlorobenzene on the Developing Immune Response of BALB/c Mice

BALB/c mice were exposed to 0.0, 0.5 and 5.0 mg/kg maternal body weight hexachlorobenzene (HCB) throughout gestation by daily per os dosing of the females. At 45 days of age selected immune functions of the offspring were assessed. The delayed-type hypersensitivity (DTH) response to oxazolone was severely depressed in animals exposed to either 0.5 or 5.0 mg/kg HCB, however, only those animals exposed to 5.0 mg/kg HCB showed a significant decrease in their mixed lymphocyte response (MLR) levels. The ability of isolated spleen cells to undergo a blastogenic response to concanavalin A (ConA), phytohemagglutinin (PHA) and lipopolysaccharide (LPS) showed no significant changes due to HCB exposure. Similarly, no significant difference in the induction of direct hemolytic plaque-forming cells was seen. A significant increase in the relative distribution of splenic T cells and a significant decrease in splenic B cells was measured in the offspring of HCB-treated females. These results suggest that HCB is capable of affecting the development or maturation of the immune response in mice, perhaps at the T cell level.