scholarly journals Positive and Negative Effects of Adenovirus Type 5 Helper Functions on Adeno-Associated Virus Type 5 (AAV5) Protein Accumulation Govern AAV5 Virus Production

2006 ◽  
Vol 81 (5) ◽  
pp. 2205-2212 ◽  
Author(s):  
Ramnath Nayak ◽  
David J. Pintel
Keyword(s):  
Virus Type ◽  
De Novo ◽  
Virus Production ◽  
Adenovirus Type ◽  
Protein Accumulation ◽  
Dependent Manner ◽  
Negative Effects ◽  
Adeno Associated Virus ◽  
Individual Effects ◽  
Adenovirus Type 5

ABSTRACT Full replication of adeno-associated virus type 5 (AAV5) is sustained by adenovirus type 5 (Ad5) helper functions E1a, E1b, E2a, E4Orf6, and virus-associated (VA) RNA; however, their combined net enhancement of AAV5 replication was comprised of both positive and negative individual effects. Although Ad5 E4Orf6 was required for AAV5 genomic DNA replication, it also functioned together with E1b to degrade de novo-expressed, preassembled AAV5 capsid proteins and Rep52 in a proteosome-dependent manner. VA RNA enhanced accumulation of AAV5 protein, overcoming the degradative effects of E4Orf6, and was thus required to restore adequate amounts of AAV5 proteins necessary to achieve efficient virus production.

scholarly journals Adeno-Associated Viruses Can Induce Phosphorylation of eIF2α via PKR Activation, Which Can Be Overcome by Helper Adenovirus Type 5 Virus-Associated RNA

2007 ◽  
Vol 81 (21) ◽  
pp. 11908-11916 ◽  
Author(s):  
Ramnath Nayak ◽  
David J. Pintel
Keyword(s):  
Cellular Response ◽  
Adenovirus Type ◽  
Capsid Gene ◽  
Protein Accumulation ◽  
Protein Kinase R ◽  
Adeno Associated Virus ◽  
Simplex Virus ◽  
Rna I ◽  
Interfering Rna ◽  
Adenovirus Type 5

ABSTRACT Mutants of adenovirus type 5 (Ad5) virus-associated RNA I deficient in inhibiting the activation and subsequent phosphorylation of protein kinase R (PKR) could neither function as helpers for adeno-associated virus type 5 (AAV5) replication nor enhance AAV5 protein accumulation in either the presence or absence of Ad5 E4Orf6 and E2a. Furthermore, a short region of the AAV5 capsid gene RNA leader sequence surrounding the AUG of VP1 could induce the phosphorylation of eIF2α. Both short interfering RNA directed against PKR and the addition of the herpes simplex virus ICP34.5 protein enhanced the accumulation of AAV5 capsid protein in the presence of the AAV5 capsid gene PKR-inducing element, suggesting that VA RNA acted to overcome direct AAV5-induced activation of PKR that led to the phosphorylation of eIF2α. The expression of both the closely related goat-derived AAV and the prototype AAV2 capsid gene transcription units also induced the phosphorylation of eIF2α, suggesting that the induction of the PKR/eIF2α cellular response may be a previously unrecognized general feature of at least the Dependovirus genus of the Parvovirinae.

scholarly journals The Interplay between Adeno-Associated Virus and Its Helper Viruses

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 662 ◽  
Author(s):  
Anita F. Meier ◽  
Cornel Fraefel ◽  
Michael Seyffert
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Adenovirus Type ◽  
Adeno Associated Virus ◽  
Basic Biology ◽  
Simplex Virus ◽  
Adenovirus Type 5

The adeno-associated virus (AAV) is a small, nonpathogenic parvovirus, which depends on helper factors to replicate. Those helper factors can be provided by coinfecting helper viruses such as adenoviruses, herpesviruses, or papillomaviruses. We review the basic biology of AAV and its most-studied helper viruses, adenovirus type 5 (AdV5) and herpes simplex virus type 1 (HSV-1). We further outline the direct and indirect interactions of AAV with those and additional helper viruses.

scholarly journals E4Orf6-E1B-55k-Dependent Degradation of De Novo-Generated Adeno-Associated Virus Type 5 Rep52 and Capsid Proteins Employs a Cullin 5-Containing E3 Ligase Complex

2008 ◽  
Vol 82 (7) ◽  
pp. 3803-3808 ◽  
Author(s):  
Ramnath Nayak ◽  
K. David Farris ◽  
David J. Pintel
Keyword(s):  
Virus Type ◽  
De Novo ◽  
E3 Ligase ◽  
Adenovirus Type ◽  
Dominant Negative ◽  
Capsid Proteins ◽  
Chain Elongation ◽  
Adeno Associated Virus ◽  
Cullin 5 ◽  
Interfering Rna

ABSTRACT Degradation of de novo-generated adeno-associated virus type 5 (AAV5) Rep52 and capsid proteins is part of the limited target specificity displayed by adenovirus type 5 E4Orf6-E1B-55k as part of a cullin 5-containing E3 ligase complex. Both Rep and capsid proteins can be found in the ligase complex, and their presence is dependent on interaction between E4Orf6 and elongins B and C. Degradation of AAV5 proteins can be inhibited by a dominant-negative ubiquitin that prevents chain elongation or by small interfering RNA directed against cullin 5.

scholarly journals Effects of Adeno-Associated Virus on Adenovirus Replication and Gene Expression during Coinfection

2006 ◽  
Vol 80 (16) ◽  
pp. 7807-7815 ◽  
Author(s):  
Jennifer M. Timpe ◽  
Kristin C. Verrill ◽  
James P. Trempe
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Virus Production ◽  
Dna Amplification ◽  
Early Gene ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Adeno Associated Virus ◽  
Transcript Levels

ABSTRACT Adeno-associated virus (AAV) is a nonpathogenic parvovirus that requires adenovirus (Ad) or another helper virus for a fully permissive infection. AAV-mediated inhibition of Ad is well documented, yet many details of this interaction remain unclear. In this study, we observed a maximum 50-fold decrease in infectious virus production and a 10- to 40-fold reduction in Ad DNA synthesis during coinfections with AAV. With the exception of the E3 gene, AAV decreased all steady-state Ad mRNA levels at 24 h postinfection (hpi) in a dose-dependent manner. However, not all transcription units were affected equally. E4 and late transcription were the most strongly inhibited, and E1A and E2A were the least affected. The temporal effects of AAV on Ad mRNA transcript levels also varied among the Ad genes. Ad protein expression paralleled mRNA levels at 24 hpi, suggesting that coinfecting AAV does not exert substantial effects on translation. In plasmid transfection assays, Rep78 protein most effectively limited Ad amplification, while Rep40 had no effect. Since E2a and E4 proteins are essential for efficient Ad DNA amplification, we examined the relationship between reduced E2A and E4 expression and decreased DNA amplification. Transfected Rep78 did not reduce E2A and E4 transcript levels prior to DNA replication. Also, AAV-induced inhibition of E2A and E4 mRNA production did not occur in the presence of hydroxyurea. It is therefore unlikely that decreased early gene expression is solely responsible for AAV's suppression of Ad DNA replication. Our results suggest that AAV amplification and/or Rep gene expression inhibits Ad DNA synthesis.

scholarly journals Impact of Natural IgM Concentration on Gene Therapy with Adenovirus Type 5 Vectors

2014 ◽  
Vol 89 (6) ◽  
pp. 3412-3416 ◽  
Author(s):  
Qi Qiu ◽  
Zhili Xu ◽  
Jie Tian ◽  
Rituparna Moitra ◽  
Sreenivasulu Gunti ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Gene Transfer ◽  
Kupffer Cells ◽  
Adenovirus Type ◽  
Dependent Manner ◽  
Lower Efficiency ◽  
Concentration Dependent Manner ◽  
Natural Igm ◽  
Adenovirus Type 5

Natural IgM inhibits gene transfer by adenovirus type 5 (Ad5) vectors. We show that polyreactive natural IgM antibodies bind to Ad5 and that inhibition of liver transduction by IgM depends on Kupffer cells. By manipulating IgM concentrationin vivo, we demonstrate that IgM inhibits liver transduction in a concentration-dependent manner. We further show that differences in natural IgM between BALB/c and C57BL/6 mice contribute to lower efficiency of Ad5 gene transfer in BALB/c mice.

scholarly journals Adeno-Associated Virus Small Rep Proteins Are Modified with at Least Two Types of Polyubiquitination

2009 ◽  
Vol 84 (2) ◽  
pp. 1206-1211 ◽  
Author(s):  
K. David Farris ◽  
Olufemi Fasina ◽  
Loretta Sukhu ◽  
Long Li ◽  
David J. Pintel
Keyword(s):  
Small Interfering Rna ◽  
Adenovirus Type ◽  
Proteasomal Degradation ◽  
Transient Transfection ◽  
Adeno Associated Virus ◽  
Rep Proteins ◽  
Cullin 5 ◽  
Interfering Rna ◽  
Adenovirus Type 5

ABSTRACT Adeno-associated virus (AAV) type 2 and 5 proteins Rep52 and Rep40 were polyubiquitinated during AAV-adenovirus type 5 (Ad5) coinfection and during transient transfection in either the presence or absence of Ad5 E4orf6 and E1b-55k. Polyubiquitination of small Rep proteins via lysine 48 (K48) linkages, normally associated with targeting of proteins for proteasomal degradation, was detected only in the presence of E4orf6. The small Rep proteins were ubiquitinated via lysine 63 (K63) following transfection in either the presence or absence of E4orf6 or following coinfection with Ad5. E4orf6/E1b-55k-dependent K48-specific polyubiquitination of small Rep proteins could be inhibited using small interfering RNA (siRNA) to cullin 5.

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