Effect of immunization with fetal cells on adenovirus-12 oncogenesis

The effect of immunization with hamster fetal cells on the tumor induction by adnovirus type 12 was studied by in vivo and in vitro. The immunization with lO-day old fetal cells showed a recognizable inhibition on the tumor induction by adenovirus type 12. The inhibition was observed only in males but not in females. For the inhibition, immnization with 107 or more cells was required. The immunization with same dose of l2-day-old fetal cells were ineffective. The inoculation of the spleen cells from hamsters immunized with un· irradiated fetal cells strongly inhibited the adenovirus·12 onocogenesis. Membrane immunofluorescent test, however, failed to demonstrate the fetal antigens in any of adnovirus-12-induced tumor cells, SV40induced tumor cells and cells from spontaneous hamster lymphoma.