Interferon responses in maternal and fetal mice.

The kinetics of maternal-fetal interferon and a chemical interferon inducer were studied in Swiss-Webster white mice at 8, 15, and 19 days of gestation. Crude interferon was administered by maternal tail vein injection to one group. There was no transfer of interferon to the fetus despite high maternal levels. A chemical interferon inducer (10-carboxymethyl-9-acridanone) was given intramuscularly to a second group. Both maternal and fetal interferon responses rapidly reached significant levels, although the fetal response was less than that of the mother. Presence of the inducer was demonstrated in both maternal and fetal samples, indicating placental transport of the chemical to the fetus. The implications of these findings for the fetal immune response are discussed.