Reduced natural killer activity in female mice after neonatal exposure to diethylstilbestrol.

Treatment of neonatal female mice with DES markedly reduced the activity of NK cells in adult mice. This finding was most evident in C57BL/6 and BALB/c strains, but was also found in outbred NMRI mice. The mechanisms behind the reduced NK activity was further analyzed. No evidence of DES-induced cellular or humoral suppressors of natural killing could be detected. Pregnancy was found to be without effects on NK. Poly I:C augmented the NK activity in control females but even very high doses of Poly I:C failed to increase the level of NK activity in neonatally DES-treated animals. The lack of response to boosting with Poly I:C was not due to alterations in kinetics of NK induction.