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At least 19 recordsLinked to original sources
PubMed2000

Nonmajor histocompatibility complex alloantigen effects on the fate of Rous sarcomas.

Rous sarcoma virus-induced tumor outcome is controlled by the MHC (B). Additional data, using controlled segregation in families, has indicated non-MHC effects as well, but few studies have focused on blood groups other than the B complex. Segregating combinations of genes encoding erythrocyte (Ea) alloantigen systems A, C, D, E, H, I, P, and L in B2B5 and B5B5 MHC (B) backgrounds were examined for their effects on Rous sarcomas. Six-week-old chickens were inoculated in the wing-web with 30 pfu of Rous sarcoma virus (RSV). Tumors were scored six times over a 10-wk period. A tumor profile index (TPI) was assigned to each chicken based on the six tumor size scores. Response was evaluated using tumor size at each measurement period, TPI, and mortality. The genotypes of Ea systems A, C, D, E, H, I, and P had no significant effect on any parameter in either B complex population. The Ea-L system had an effect on Rous sarcomas in the B2B5 intermediate responders and B5B5 progressors. Tumor size, TPI, and mortality were all significantly lower in B2B5 L1L1 chickens than in B2B5 L1L2 chickens. Mortality was lower in the B5B5 L1L1 birds than in B5B5 L1L2 chickens. It appears that the Ea-L system, or one closely linked, is acting in a manner independent of the B complex in response to RSV challenge.

Animals↗
PubMed1982

Fusion injection of Rous Sarcoma virus proteins into Rous sarcoma virus-transformed, non-producing hamster cells causes release of infectious virus.

Purified virus proteins from transformation-defective (td) mutants of Rous sarcoma virus PrA or PrB were trapped in human erythrocyte ghosts which, after resealing, were fusion-injected into hamster RBH cells or rat TWERC cells. These cell lines are non-productively transformed by subgroup C Rous sarcoma virus. After fusion injection the hamster RBH cells released transforming subgroup C Rous sarcoma virus. No infectious virus could be rescued from rat TWERC cells. Since previous experiments have shown that fusion injection of the purified Rous sarcoma virus protein p15 into hamster RBH cells caused cleavage of the precursor protein pr76 to form the virus group-specific antigen (gag) but did not induce infectious virus, we conclude that in addition to p15 other virus proteins are required to induce virus rescue in hamster RBH cells.

Animals↗
PubMed1972

Rescue of rous sarcoma virus from rous sarcoma virus-transformed mammalian cells.

Rat cells transformed by the B77 strain of avian sarcoma virus produce no virus-like particles, yet B77 virus was rescued from these cells by Sendai virus-mediated fusion with chicken cells. This virus rescue was not affected by treatment of the chicken cells with agents that rendered the cells incapable of dividing, although such treatment greatly reduced the ability of the chicken cells to plate as infectious centers after infection with B77 virus. Fusion of R(B77) cells with chicken erythrocytes also led to virus rescue, although with less efficiency than fusion with chicken fibroblasts. Therefore, virus rescue was probably due to a factor or factors contributed by chicken cells which aid in virus production.

Animals↗
PubMed1971

Comparison of Rous sarcoma virus-specific deoxyribonucleic acid polymerases in virions of Rous sarcoma virus and in Rous sarcoma virus-infected chicken cells.

Labeled virions of Rous sarcoma virus (RSV) were disrupted with detergent and analyzed on equilibrium sucrose density gradients. A core fraction at a density of approximately 1.24 g/cc contained all of the (3)H-uridine label and about 30% of the (3)H-leucine label from the virions. Endogenous viral deoxyribonucleic acid (DNA) polymerase activity was only found in the same location. Additional ribonucleic acid (RNA)- and DNA-dependent DNA polymerase activities were found at the top of the gradients. RNA-dependent and DNA-dependent DNA polymerase activities were also found in RSV-converted chicken cells. Particles containing these activities were released from cells by detergent and were shown to contain viral RNA. These particles were analyzed on equilibrium sucrose density gradients and were found to have densities different from virion cores.

Animals↗
PubMed1978

[Complementary RNA in the chicken sarcoma cells and Rous sarcoma virus].

The subcellular localization in chicken Rous sarcoma of nucleotide sequence, complementary to Rous sarcoma virus RNA was examined by RNA/RNA molecular hybridization. The preparations of radioiodinated virion RNA were annealed with RNAs from different fractions (nuclei, mitochondria, free and membrane-bound polyribosomes) isolated from chicken Rous sarcoma. Formation of RNA-ase resistant hybrids between the viral 125I-RNA and RNA from the mitochondria and membrane-bound polyribosomes was revealed. The latter were characterized by a higher relative redundancy of nucleotide sequences complementary to virion RNA than that in the former, by factor 446. The role of complementary ribonucleotide sequences is discussed.

Animals↗
PubMed1976

Avian leukosis viruses of different subgroups and types isolated after passage of Rous sarcoma virus-Rous-associated virus-0 in cells from different ring-necked pheasant embryos.

Avian leukosis viruses of subgroups A and F (RAV-A and RAV-F) arose at a low rate after passage of Rous sarcoma virus-Rous-associated virus-0, which is subgroup E, in cells from ring-necked pheasant embryos. In cells of two embryos, all of the viruses isolated after virus passage were RAV-F. However, in cells of a third embryo, both RAV-A and RAV-F were isolated. In addition, there sometimes were type-specific differences among the different isolates of RAV-A and RAV-F from the cells of single embryos. These results indicate that the RAV-A and RAV-F probably arose by recombination of viral and cellular genes, that different ring-necked pheasant embryo may have different endogenous avian leukosis virus-related nucleotide sequences, and that recombination at different sites in these endogenous sequences might give rise to type-specific differences among the RAV-A and RAV-F.

Animals↗
PubMed1984

Homologies between a brain-specific identifier (ID) sequence and regions of Harvey murine sarcoma virus and Rous sarcoma virus genomes. Putative role of identifier sequences in the tissue specificity of malignant transformation by RNA tumor viruses.

As a step toward understanding of the tissue specificity of cellular transformation by RNA tumor viruses were looked for the presence of a putative brain specific regulatory (identifier) sequence (C82B) in the genome of various oncornaviruses. The genomes of Harvey murine sarcoma virus and Rous sarcoma virus contain sequences flanking the viral oncogenes with greater than 80% and greater than 60% homology to C82B, respectively. We suggest that identifier sequences acquired by oncoviruses may determine the potential target cells of malignant transformation after virus penetration.

Animals↗
PubMed1985

Partial nucleotide sequence of Rous sarcoma virus-29 provides evidence that the original Rous sarcoma virus was replication defective.

Rous sarcoma virus-29 (RSV-29) is the strain of RSV that has the least number of passages beyond its isolation from chicken tumor no. 1 among all current strains of RSV. Biological characterization indicated that it was replication defective. RNA analysis of nonproducer clones of RSV-29-infected chicken embryonic fibroblasts showed the presence of a subgenomic message of 2.6 kilobases containing src and a genomic RNA of 7.7 kilobases that contains gag, pol, and src, but not env. The src-containing EcoRI fragment of RSV-29 proviral DNA was molecularly cloned. Sequence analysis of the regions flanking src revealed that the env gene was completely deleted in RSV-29 and that the sequence across the deletion was exactly the same as the Bryan high-titer strain of RSV. The sequence immediately 3' to src in RSV-29 was closely related to that of the Prague strain of RSV. The fact that the strain of RSV which has the minimal number of passages beyond its isolation is replication defective supports the hypothesis of Lerner and Hanafusa (J. Virol. 49:549-556, 1984) that the original RSV is a defective transforming virus. This defective transforming virus is postulated to be the precursor to other defective RSVs like the Bryan high-titer strain and to nondefective RSVs like the Prague strain. The particular clone of RSV-29 that we studied also had a short stretch of sequence duplication at the 3' end of the pol gene, which was presumably created by an error of reverse transcription.

Animals↗
PubMed1989

Comparison of the regional distribution of calspectin (nonerythroid spectrin or fodrin), alpha-actinin, vinculin nonerythroid protein 4.1, and calpactin in normal and avian sarcoma virus- or Rous sarcoma virus-induced transformed cells.

With fluorescence and interference reflection microscopy (IRM), we compared the regional distribution of calspectin, its interacting proteins (nonerythroid protein 4.1 and calpactin), alpha-actinin, and vinculin in NRK cells and their avian sarcoma virus (ASV)- or temperature-sensitive (ts) Rous sarcoma virus (RSV)-transformed cells. The localization of these cytoskeletal proteins was determined with the specific antibodies. In NRK cells, alpha-actinin and vinculin were concentrated at adhesion plaques. By contrast, calspectin was distributed throughout the cytoplasm, but not concentrated at adhesion plaques. In ASV- and ts RSV-transformed cells, all three cytoskeletal proteins were concentrated at dot structures representing cellular feet. Nonerythroid protein 4.1 and calpactin were diffusely distributed throughout the cytoplasm of NRK cells and their transformed counterparts. In the case of calpactin, a part of this protein was excluded near regions of the terminal ends of stress fibers. These two proteins did not show the restricted location at the dot structures of transformed cells. From these findings, it is apparent that the accumulation of calspectin into dot structures is a specific event for cell transformation induced by the src protein.

Actinin↗
PubMed1971

Mechanism of oncogenic transformation by Rous sarcoma virus. II. Effect of rifampin on Rous sarcoma virus infection.

Rifampin partially inhibits focus formation and virus production in chick embryo fibroblasts infected with Bryan high-titer Rous sarcoma (RAV-1) virus. This inhibition occurs with exposure to rifampin during a critical period between day 1 and day 2 after infection. This suggests that the drug does not affect formation of the provirus or its transcription or translation after the "fixation" step, but it seems to affect one or more events which take place before fixation and activation of virus production.

Animals↗
PubMed1978

Effects of prophylactic treatment with the methanol extraction residue fraction of tubercle bacilli (MER) on the development of Rous sarcomas of chickens following challenge with the Rous sarcoma virus.

Three-month-old chickens were treated with the methanol extraction residue fraction of tubercle bacilli (MER) under different conditions, and subsequently challenged with living Rous sarcoma virus. The birds developed progressively growing sarcomas following viral challenge. A substantial proportion of the hosts which had been pretreated with MER under optimal circumstances (38 to 58%) showed complete and long-lasting regression of the neoplasms, and the survival of many of the animals that did succumb to progressively growing tumors was prolonged. An absolute condition for prophylactic efficacy of MER treatment in this model system was injection of the agent into the same body area (wing) into which subsequent viral challenge was introduced. The quantity of MER employed and the timing of the prophylactic administration were also decisive variables.

Animals↗