title: Prevention of murine sarcoma virus oncogenesis in offspring of immunized female mice.
abstract: BALB/c mice born to and nursed by females immunized against MSV-M showed a reduced tumour incidence and a high tumour regression rate following MSV-M injection at 7-14 days of age. Females immunized long before mating could also confer protection to their offspring whereas females immunized after parturition could not. A reduced number of tumours was observed in 3 out of 14 MSV-M injected litters whose mothers had been previously exposed to the virus while nursing infected offspring. Sera from suckling mice born to and nursed by immunized mothers contained MSV-M neutralizing antibody as shown by an in vitro focus reduction assay. Cell-free extracts from mice which developed leukaemia after MSV-M inoculation were tested for oncogenic activity in 1-week old mice. Out of 6 extracts, 4 induced typical MSV-M tumours and 2 caused leukaemias.
mesh_terms: D000818:Animals; D005260:Female; D007114:Immunization; D007942:Leukemia, Experimental; D008431:Maternal-Fetal Exchange; D051379:Mice; D008807:Mice, Inbred BALB C; D008979:Moloney murine leukemia virus / Q000472:pathogenicity*; D009500:Neutralization Tests; D011247:Pregnancy; D012513:Sarcoma, Experimental / Q000517:prevention & control*