title: Reciprocal inhibition of mouse leukemia virus infection by Fv-1 allele cell extracts.
abstract: Soluble extracts of mouse cells with Fv-1(n) or Fv-1(b) gene alleles specifically and reciprocally inhibit infection of B- or N-tropic mouse leukemia viruses in permissive cell cultures. NB-tropic virus infection was not inhibited by either cell extract. Extracts from Fv-1(-) cells did not inhibit infection by the three virus host-range types, but N- or B-tropic virus infection of Fv-1(-) cells was inhibited by extracts of the nonpermissive cells, and Fv-1(nb) cell extracts inhibited both viruses. The maximum degree of inhibition was 50-80% as determined by immunofluorescent or plaque assays, with extracts containing up to 500 mug/ml of nonpermissive cell protein. The inhibitor(s) is relatively unstable since activity is lost after 2 hr at 37 degrees or 30 min at 56 degrees . The inhibitor(s) was most effective if added 2 hr before or within 2 hr after infection, did not react with the virus directly, inhibit virus attachment, or inhibit the normal cell functions tested. These results indicate that nonpermissive mouse cells contain a product, possibly determined by the Fv-1 gene, which inhibits some early postpenetration event(s) in leukemia virus infection.
mesh_terms: D000483:Alleles; D000818:Animals; D002460:Cell Line; D004279:DNA, Viral / Q000096:biosynthesis; D004622:Embryo, Mammalian; D005347:Fibroblasts; D005838:Genotype; D009052:Leukemia Virus, Murine / Q000254:growth & development*; D051379:Mice; D008807:Mice, Inbred BALB C; D013045:Species Specificity; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D010948:Viral Plaque Assay; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D014316:Tritium; D013936:Thymidine