The effect of prenatal chlordane exposure on specific anti-influenza cell-mediated immunity.

Previous studies in our laboratory have documented that in utero chlordane exposure caused a significant enhancement in the survival of the offspring to influenza A virus infection, and a depressed delayed type hypersensitivity (DTH) response to oxazolone. To correlate these 2 effects, we assayed influenza A virus-specific DTH response, and found that it was significantly decreased in chlordane-treated offspring. Virus-specific T-cell blastogenesis was also assayed in chlordane-treated animals. No significant differences due to the chlordane treatment were found in virus-specific T-cell blastogenesis, suggesting that the DTH depression did not result from a paucity of antigen-reactive T-cells. To determine whether enhanced survival was due, in part, to the effects of chlordane on virus replication, rather than on immunological alteration alone, the kinetics of influenza virus replication in the lungs of chlordane- and vehicle-treated animals were determined. In utero chlordane treatment caused no significant differences in in vivo virus replication. These data suggest that increased survival was due to a decrease in virus-specific DTH and its associated pathology.