title: The involvement of a type-B retrovirus in the induction of thymic lymphomas.
abstract: A highly leukemogenic virus (DMBA-LV) (in vivo leukemogenic titer 1-5 X 10(6) IU/ml, and 35-40 days to thymic lymphoma detection) is produced by a chemical carcinogen-induced transplanted thymic lymphoma. The virus preparation is a mixture of a type-B retrovirus highly related to exogenous type-B retroviral isolates and a biologically defective type-C retrovirus. The DNA of DMBA-LV-induced-tumors contains new type-B proviruses but no additional type-C proviruses could be detected. The leukemogenicity of DMBA-LV was completely neutralized by a monoclonal antibody against MMTV envelope glycoprotein, but was not affected by a broadly reacting Friend MuLV anti-gp70 serum which effectively neutralizes type-C ecotropic, xenotropic, and recombinant retroviruses and which completely abolishes the leukemogenic activity of Moloney leukemia virus. Three type-B mammary tumor-inducing retroviral isolates, while containing type-C retroviral sequences, were not leukemogenic. A further characterization of the type-C retroviral sequences present in DMBA-LV indicated that sequences characteristic of endogenous, nonxenotropic proviruses are present. In addition, using a variety of type-C-specific retroviral DNA probes, no evidence was obtained for the presence of a type-B-C-recombinant genome in DMBA-LV. Leukemogenesis was absolutely dependent upon the presence of a functional type-B retroviral envelope gp 52 and DMBA-LV does not appear to contain a leukemogenic retroviral type-C genome.
authors.forename: J K
authors.initials: JK
authors.lastname: Ball
authors.forename: L O
authors.initials: LO
authors.lastname: Arthur
authors.forename: G A
authors.initials: GA
authors.lastname: Dekaban
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000302:isolation & purification; D005260:Female; D009052:Leukemia Virus, Murine / Q000472:pathogenicity*; D007942:Leukemia, Experimental / Q000382:microbiology*; D008223:Lymphoma / Q000382:microbiology*; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000382:microbiology; D008324:Mammary Tumor Virus, Mouse / Q000276:immunology / Q000302:isolation & purification; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D008892:Milk / Q000382:microbiology; D011247:Pregnancy; D013953:Thymus Neoplasms / Q000382:microbiology*
chemical_list: D000911:Antibodies, Monoclonal; D004279:DNA, Viral; D004262:DNA Restriction Enzymes