Altered expression of adenovirus 12 DNA-binding protein but not DNA polymerase during abortive infection of hamster cells

Lucher, Lynne A.; Khuntirat, Benjawan; Zhao, Jiansheng; Angeletti, Peter C.

doi:10.1016/0042-6822(92)90694-k

Cited by 7 publications

(5 citation statements)

References 27 publications

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“…That these sites exist is suggested by indirect immunofluorescence experiments that showed that Ad replication proteins are present at punctate sites within the nucleus (11,24,42), perhaps within large complexes of NM proteins. Localized concentrations of viral factors may be critical for the occurrence of successful Ad DNA replication (32). For example, it has been shown that the Ad replication protein, DNA-binding protein, is part of a 650-kDa, high-salt, stable complex which contains both DNA binding and kinase activities (45).…”

Section: Discussionmentioning

confidence: 99%

Tyrosine kinase-dependent release of an adenovirus preterminal protein complex from the nuclear matrix

Angeletti

Engler

1996

J Virol

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Adenovirus (Ad) replicative complexes form at discrete sites on the nuclear matrix (NM) through the interaction of Ad preterminal protein (pTP). The NM is a highly salt-resistant fibrillar network which is known to anchor transcription, mRNA splicing, and DNA replication complexes. Incubation of rATP with NM to which pTP was bound caused the release of pTP as a pTP-NM complex with a size of 220 to 230 kDa; incubation with 5 adenylylimidodiphosphate (rAMP-PNP) showed no significant release, indicating that rATP hydrolysis was required. With NM extracts, it was shown that a pTP-NM complex which was capable of binding Ad origin DNA could be reconstituted in vitro. A number of high-molecular-weight NM proteins ranging in size from 120 to 200 kDa were identified on Far Western blots for their ability to bind pTP. rATP-dependent release of pTP from the NM was inhibited in a dose-dependent fashion by the addition of tyrosine kinase inhibitors, such as quercetin, methyl-2,5-dihydroxycinnamate, or genistein. NM-mediated phosphorylation of a poly(Glu, Tyr) substrate was also significantly abrogated by the addition of these compounds. rATP-dependent release of Ad DNA termini bound to the NM via pTP was also blocked by the addition of these inhibitors. These results indicate that a tyrosine kinase mechanism controls the release of pTP from its binding sites on the NM. These data support the concept that phosphorylation may play a key role in the modulation of pTP binding sites on the NM.

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Section: Discussionmentioning

confidence: 99%

Tyrosine kinase-dependent release of an adenovirus preterminal protein complex from the nuclear matrix

Angeletti

Engler

1996

J Virol

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“…However, the expression of the DBP gene lagged behind that observed in ovine and nonovine fibroblasts. Diminished expression of E2 genes was suggested as a major cause of the early block in Ad12 replication in hamster cells, although reports about the levels of single E2 gene products are contradictory (21,36). Reduced amounts of E1 mRNAs were also reported for abortive Ad12 infection (35).…”

Section: Discussionmentioning

confidence: 99%

Biology of Ovine Adenovirus Infection of Nonpermissive Cells

Kümin¹,

Hofmann²,

Rudolph

et al. 2002

J Virol

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Nonhuman adenoviruses, including those of the genus Atadenovirus, have the potential to serve as vectors for vaccine and gene therapy applications in humans, since they are resistant to preexisting immunity induced by human adenoviruses in the majority of the population. In this study, we elucidate the outcome of infection by ovine adenovirus type 7 isolate 287 (OAdV) of several nonovine cell types. We show here that OAdV infects a wide range of nonovine cells but is unable to complete its replication cycle in any of them. In nonovine, nonfibroblast cells, viral replication is blocked at an early stage before the onset of, or early in, DNA replication. Some fibroblasts, on the other hand, allow viral DNA replication but block virus production at a later stage during or after the translation of late viral proteins. Late viral proteins are expressed in cells where viral DNA replication takes place, albeit at a reduced level. Significantly, late proteins are not properly processed, and their cellular distribution differs from that observed in infected ovine cells. Thus, our results clearly show that OAdV infection of all nonovine cells tested is abortive even if significant viral DNA replication occurs. These findings have significant positive implications with respect to the safety of the vector system and its future use in humans.Human adenoviruses have been widely studied over the last 4 decades, and the processes involved in infection and replication have been largely characterized. Abortive infection by human adenoviruses has been investigated in human and several nonhuman cell culture systems (reviewed in reference 35). These studies have provided a better understanding of the molecular biology of human adenoviruses and of events such as the integration of foreign DNA into mammalian genomes and the initiation of malignant transformation by DNA tumor viruses. However, the biology of human adenovirus infection in heterologous cells differs widely for various genotypes, even in the same cell line. For example, baby hamster kidney cells (BHK-21) are semipermissive for adenovirus type 2 (Ad2) and Ad5 replication but block infection with Ad3 and Ad12 at an early step of the viral life cycle (13). The early block in Ad12 replication can be abrogated by constitutive expression of E1 genes from Ad2, -

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“…This abortive infection was bypassed by overexpressing the adenovirus serotype 5 E1 region in cell culture. In this case, E1 region overexpression was sufficient to circumvent transcriptional blocks in this model (22). These studies indicate that expression of viral genes or coinfection with other viruses may provide the unknown factors required to allow the progression of an abortive infection.…”

Section: Discussionmentioning

confidence: 71%

Transcriptional Blocks Limit Adenoviral Replication in Primary Ovarian Tumor

Preuss

Lam

Wang

et al. 2004

Clinical Cancer Research

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Purpose: Despite the success of conditionally replicating adenoviruses in tumor models, clinical success has been limited when they are used as a single modality agent. Overcoming the disparity in efficacy between in vivo animal models and human use is a key hurdle for better conditionally replicating adenovirus therapy in humans. We endeavored to identify biological blocks to adenoviral infection and replication in tumor cells.Experimental Design: We hypothesized that the differences in adenoviral replication between ovarian cancer cell lines and patient tumor samples are the result of a block in viral RNA transcription. To test this hypothesis, established ovarian cancer cell lines and purified patient ovarian cancer cells were infected with wild-type adenovirus. RNA for early adenoviral genes E1A and E1B as well as the late transcripts for fiber and hexon were measured using real-time PCR.Results: Established ovarian cancer cell lines treated with wild-type virus had a lower E1A:E1B ratio than the patient samples. Additionally, the levels of fiber and hexon relative to E1A were also decreased in the patient samples compared with the established cell lines. These findings were consistent with an early-to late-phase block in the adenovirus replication cycle.Conclusions: These data suggest that the biology of abortive infection in the patient samples may be linked to a defect in the production of early and late viral transcripts.Identification of factors leading to abortive infection will be crucial to understanding the low viral replication in patient samples.

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Altered expression of adenovirus 12 DNA-binding protein but not DNA polymerase during abortive infection of hamster cells

Cited by 7 publications

References 27 publications

Tyrosine kinase-dependent release of an adenovirus preterminal protein complex from the nuclear matrix

Tyrosine kinase-dependent release of an adenovirus preterminal protein complex from the nuclear matrix

Biology of Ovine Adenovirus Infection of Nonpermissive Cells

Transcriptional Blocks Limit Adenoviral Replication in Primary Ovarian Tumor

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