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Characteristics of the Major Internal Protein and RNA-Dependent DNA Polymerase of Bovine Leukaemia Virus

1975; Microbiology Society; Volume: 29; Issue: 3 Linguagem: Inglês

10.1099/0022-1317-29-3-305

1465-2099

Raymond V. Gilden, Clarine Long, Maureen R. Hanson, Robert Toni, Howard P. Charman, Stephen Oroszlan, Janice Μ. Miller, M. J. Van Der Maaten,

T-cell and Retrovirus Studies

Summary A virus designated bovine leukaemia virus (BLV), associated with leukaemia in cattle and previously demonstrated to induce the disease in sheep, was purified from chronically infected sheep cell cultures. Electrophoretic analysis showed a major protein of mol. wt. about 24000 (p24) which reacted in gel diffusion and complement-fixation tests with sera from naturally infected cattle, experimentally infected sheep, and guinea pigs immunized with p24. BLV p24 has an isoelectric point of 8.6. Interspecies antigenic reactivities characteristic of mammalian Type C virus p30s were not detected in disrupted BLV or on p24. Sheep and guinea pig antisera to BLV, reactive withp 24, also did not precipitate several Type C virus p30s in radioimmunoassays. BLV is also distinguished from Type C viruses and resembles mouse mammary tumour virus and Mason-Pfizer virus in having an RNA-dependent DNA polymerase which is preferentially active in the presence of Mg++ when synthetic templates are used. Along with previously published morphological data, the above indicates that BLV is not a Type C virus as classically defined. Four hundred and forty one human sera from cancer patients and matched controls were non-reactive with disrupted BLV, BLV infected cells, and BLV p24 in complement-fixation tests.