ONCORNA-VIRUS-INDUCED SARCOMA FORMATION OBSCURED BY RAPID DEVELOPMENT OF LETHAL LEUKEMIA

  • 1 January 1977
    • journal article
    • research article
    • Vol. 37  (1) , 59-63
Abstract
Injection i.v. of avian erythroblastosis virus (AEV) strain ES4 causes a high incidence of leukemia and the death of most of the inoculated chicks within 2 wk. As found earlier, the virus is defective for replication and transforms [chick] bone marrow cultures in vitro and chick embryo fibroblasts. Inoculation of transformed AEV cells negative for virus production into newborn chicks induced the formation of sarcomas only, whereas cells superinfected with helper virus induced the formation of erythroblastosis in addition to sarcomas. The helper virus alone caused neither sarcomas nor erythroblastosis during the experimental period. These findings were explained by the hypothesis that AEV-induced erythroblastosis develops more rapidly than do AEV-induced sarcomas and that animals receiving i.v. injections die of the leukemia before sarcomas become detectable. The observation that animals receiving i.m. injections of AEV developed sarcomas at the site of injection strongly supports this concept. Most of the animals that received i.m. injections also developed an erythroblastosis that was delayed in comparison to the animals receiving i.v. injections. The erythroblastosis induced by AEV apparently does not suppress the formation of sarcomas in the same animal.