Multiple Free Viral DNA Copies in Polyoma Virus-Transformed Mouse Cells Surviving Productive Infection

Magnusson, Göran; Nilsson, Maj-Greth

doi:10.1128/jvi.22.3.646-653.1977

Cited by 21 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A remarkable feature of these cells is the persistence of homogeneous, free BKV genomes after several years in culture. These findings are in contrast to rodent cells transformed by wild type or ts mutants of polyoma virus (16,20,21,32,34) in which a rather heterogeneous population of free genomes were found along with integrated viral DNA sequences. Furthermore, in the polyoma virus-transformed rat cells, the free viral DNA, found only in a minority of the cell population, appeared to arise after release or excision of genomes existing in an integrated state (34).…”

Section: Resultscontrasting

confidence: 75%

Persistent BK papovavirus infection of transformed human fetal brain cells. I. Episomal viral DNA in cloned lines deficient in T-antigen expression

Takemoto¹,

Linke²,

Miyamura³

et al. 1979

J Virol

View full text Add to dashboard Cite

After infection of permissive human fetal brain cells by BK human papovavirus (BKV), the vast majority of the cells were killed by the virus, but rare survivors were recovered after frequent medium changes. These surviving cells grew and formed visible colonies after 5 to 6 weeks and were thereafter established as permanent cell lines. These cells, designated as BK-HFB cells, were persistently infected and shed BKV. Morphologically, they were small, polygonal cells and had transformed growth properties. Their plating efficiency on solid substrates or in semisolid medium was high, and they were tumorigenic in athymic nude mice. Cloning experiments in medium containing BKV antiserum revealed that BKV did not persist in the cultures in a simple carrier state. All cloned cell lines were initially T-antigen negative and virus-free. However, every clone began to release BKV and again became persistently infected within 3 weeks after removal of BKV antiserum. After rigorous antibody treatment, four of seven clones still released virus spontaneously upon removal of antiserum; three clones have remained virus-free and are apparently cured. Although these cloned cell lines are T-and V-antigen negative when grown in antiserum-containing medium, they retain "free" or episomal BKV genomes; integrated viral DNA was not detected in any of the clones. These free genomes are indistinguishable from prototype BKV DNA and are found in much larger amounts in virus-shedding cell lines.

show abstract

Section: Resultscontrasting

confidence: 75%

Persistent BK papovavirus infection of transformed human fetal brain cells. I. Episomal viral DNA in cloned lines deficient in T-antigen expression

Takemoto¹,

Linke²,

Miyamura³

et al. 1979

J Virol

View full text Add to dashboard Cite

show abstract

“…Covalently closed circular viral DNA was selectively extracted (15) from 3T6 cells that had been infected at a multiplicity of 5 to 10 PFU/cell. The DNA was purified further by centrifugation to equilibrium in CsCl-ethidium bromide gradients and sedimentation in 5 to 20% neutral sucrose gradients (22).…”

mentioning

confidence: 99%

Construction and analysis of viable deletion mutants of polyoma virus

Magnusson¹,

Berg²

1979

J Virol

View full text Add to dashboard Cite

Viable mutants of polyoma with small deletions ranging in size from 2 to 75 base pairs were obtained by infecting 3T3 cells with polyoma DNA that had been cleaved once with HaeII endonuclease or with DNase-Mn2" digestion. The HaeII endonuclease-cleaved DNA yielded mutants with deletions at map position 72-73, whereas the mutants generated by DNase I-Mn2' digestion had deletions either at map position 72-73 or within the map coordinates 92 and 99. Both groups of mutants appeared to grow as well as wild-type virus in 3T3 cells. The deletions at map position 72-73 did not alter the virus's ability to transform rat cells. Hence, the region just to the early side of the origin of DNA replication is not essential for vegetative growth or transformation. But the mutants with deletions in the region between map coordinates 92 and 99, a segment thought to code for polyoma large and middle T antigens (

show abstract

“…Recombinant Plasmid The mammalian expression vector pSV,-dhfr carries simian virus 40 (SV40) early promoter, origin for DNA replication, SV40 poly-A site, splicing site, and the dhfr gene (Magnuson and Nilsson, 1977;Subramani and Southern, 1983). Reconstruction of the expression vector from pSV,-dhfr to pSV2-EP is depicted in Figure 1.…”

Section: Construction Of Vectors Andmentioning

confidence: 99%

Expression of a gene encoding a rabbit sperm membrane protein in mammalian cells

Liu

Wang

Miao

et al. 1992

Molecular Reproduction Devel

View full text Add to dashboard Cite

A general mammalian expression vector designated pSV2-EP was reconstructed by inserting an oligonucleotide fragment into pSV2-dhfr. This vector allowed insertion of cDNAs with EcoRI cohesive ends. The pSV2-EP contains a simian virus 40 (SV40) early promoter, origin for DNA replication, SV40 poly-A site, splicing site, an initiator ATG downstream from the promoter and an EcoRI site for the insertion of cDNA fragment screened from lambda gt11 expression libraries. A recombinant plasmid (pS-VRS-1) was constructed by inserting RSD-1, a cDNA encoding a rabbit sperm tail protein, into the EcoRI site of the pSV2-EP vector. Chinese hamster ovarian (CHO) dhfr-negative cells were cotransformed with pSV2-dhfr and pSVRS-1 by the calcium phosphate method. In selective culture medium without thymidine and hypoxanthine, several cell lines were obtained containing mRNA and DNA that hybridized with RSD-1. One of these transformed cell lines stained intensely with anti-rSMP-B antibodies, demonstrating that the RSD-1 was expressed in the transformed CHO cells.

show abstract

Multiple Free Viral DNA Copies in Polyoma Virus-Transformed Mouse Cells Surviving Productive Infection

Cited by 21 publications

References 22 publications

Persistent BK papovavirus infection of transformed human fetal brain cells. I. Episomal viral DNA in cloned lines deficient in T-antigen expression

Persistent BK papovavirus infection of transformed human fetal brain cells. I. Episomal viral DNA in cloned lines deficient in T-antigen expression

Construction and analysis of viable deletion mutants of polyoma virus

Expression of a gene encoding a rabbit sperm membrane protein in mammalian cells

Contact Info

Product

Resources

About