title: Analysis of two strains of Friend murine leukemia viruses differing in ability to induce early splenomegaly: lack of relationship with generation of recombinant mink cell focus-forming viruses.
abstract: Friend murine leukemia helper viruses (F-MuLV) 57 and B3 were indistinguishable by genomic structural analyses with RNase T1-resistant oligonucleotide fingerprinting and by antigenic reactivity with a panel of 31 monoclonal antibodies directed against murine leukemia viruses. Nevertheless, F-MuLV 57 and B3 had strikingly different virulences. Approximately 2 months after inoculation, IRW and NFS/N mice inoculated as newborns with F-MuLV 57 had gross splenomegaly caused by erythroid proliferation. In contrast, an equivalent dose of F-MuLV B3 induced spleen or lymph node enlargement 4 to 13 months after inoculation. Although most cases of spleen enlargement in F-MuLV B3-inoculated mice were due to erythroid proliferation, lymphoid or myeloid proliferation was also frequently observed. The replication of both F-MuLV 57 and B3 was equally efficient, and both viruses generated recombinant dual-tropic mink cell focus-forming (MCF) viruses with the same kinetics and efficiency. Moreover, MCF viruses induced by F-MuLV 57 and B3 had the same antigenic patterns. Therefore, the ability of F-MuLV to induce early splenomegaly did not correlate with the generation of recombinant MCF viruses.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D004920:Erythropoiesis; D005622:Friend murine leukemia virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D006378:Helper Viruses / Q000235:genetics / Q000472:pathogenicity*; D009052:Leukemia Virus, Murine / Q000302:isolation & purification*; D051379:Mice; D008908:Mink Cell Focus-Inducing Viruses / Q000235:genetics / Q000302:isolation & purification*; D012367:RNA, Viral / Q000032:analysis; D011995:Recombination, Genetic; D013163:Splenomegaly / Q000209:etiology* / Q000382:microbiology; D014412:Tumor Virus Infections / Q000150:complications / Q000503:physiopathology; D014774:Virulence; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral