scholarly journals Adeno-associated virus Rep proteins antagonize phosphatase PP1 to counteract KAP1 repression of the latent viral genome

2018 ◽  
Vol 115 (15) ◽  
pp. E3529-E3538 ◽  
Author(s):  
Sarah Smith-Moore ◽  
Stuart J. D. Neil ◽  
Cornel Fraefel ◽  
R. Michael Linden ◽  
Mathieu Bollen ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Helper Virus ◽  
Protein Phosphatase 1 ◽  
Wild Type ◽  
Fha Domain ◽  
Adeno Associated Virus ◽  
Histone 3 ◽  
Rep Proteins ◽  
Cellular Factors

Adeno-associated virus (AAV) is a small human Dependovirus whose low immunogenicity and capacity for long-term persistence have led to its widespread use as vector for gene therapy. Despite great recent successes in AAV-based gene therapy, further improvements in vector technology may be hindered by an inadequate understanding of various aspects of basic AAV biology. AAV is unique in that its replication is largely dependent on a helper virus and cellular factors. In the absence of helper virus coinfection, wild-type AAV establishes latency through mechanisms that are not yet fully understood. Challenging the currently held model for AAV latency, we show here that the corepressor Krüppel-associated box domain-associated protein 1 (KAP1) binds the latent AAV2 genome at the rep ORF, leading to trimethylation of AAV2-associated histone 3 lysine 9 and that the inactivation of KAP1 repression is necessary for AAV2 reactivation and replication. We identify a viral mechanism for the counteraction of KAP1 in which interference with the KAP1 phosphatase protein phosphatase 1 (PP1) by the AAV2 Rep proteins mediates enhanced phosphorylation of KAP1-S824 and thus relief from KAP1 repression. Furthermore, we show that this phenomenon involves recruitment of the NIPP1 (nuclear inhibitor of PP1)–PP1α holoenzyme to KAP1 in a manner dependent upon the NIPP1 FHA domain, identifying NIPP1 as an interaction partner for KAP1 and shedding light on the mechanism through which PP1 regulates cellular KAP1 activity.

scholarly journals Regulation of Adeno-Associated Virus DNA Replication by the Cellular TAF-I/Set Complex

2006 ◽  
Vol 80 (14) ◽  
pp. 6855-6864 ◽  
Author(s):  
Gianluca Pegoraro ◽  
Alessandro Marcello ◽  
Michael P. Myers ◽  
Mauro Giacca
Keyword(s):  
Nuclear Protein ◽  
De Novo ◽  
Viral Vector ◽  
Interacting Proteins ◽  
Wild Type ◽  
Adeno Associated Virus ◽  
Factor I ◽  
Acidic Domain ◽  
Rep Proteins ◽  
Cellular Factors

ABSTRACT The Rep proteins of the adeno-associated virus (AAV) are required for viral replication in the presence of adenovirus helper functions and as yet poorly characterized cellular factors. In an attempt to identify such factors, we purified Flag-Rep68-interacting proteins from human cell lysates. Several polypeptides were identified by mass spectrometry, among which was ANP32B, a member of the acidic nuclear protein 32 family which takes part in the formation of the template-activating factor I/Set oncoprotein (TAF-I/Set) complex. The N terminus of Rep was found to specifically bind the acidic domain of ANP32B; through this interaction, Rep was also able to recruit other members of the TAF-I/Set complex, including the ANP32A protein and the histone chaperone TAF-I/Set. Further experiments revealed that silencing of ANP32A and ANP32B inhibited AAV replication, while overexpression of all of the components of the TAF-I/Set complex increased de novo AAV DNA synthesis in permissive cells. Besides being the first indication that the TAF-I/Set complex participates in wild-type AAV replication, these findings have important implications for the generation of recombinant AAV vectors since overexpression of the TAF-I/Set components was found to markedly increase viral vector production.

scholarly journals Complete Correction of Brain and Spinal Cord Pathology in Metachromatic Leukodystrophy Mice

2021 ◽  
Vol 14 ◽  
Author(s):  
Emilie Audouard ◽  
Valentin Oger ◽  
Béatrix Meha ◽  
Nathalie Cartier ◽  
Caroline Sevin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Gene Therapy ◽  
Metachromatic Leukodystrophy ◽  
Early Death ◽  
Lysosomal Storage ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
Brain And Spinal Cord ◽  
Sulfatide Accumulation

Metachromatic leukodystrophy (MLD) is a lysosomal storage disorder characterized by accumulation of sulfatides in both glial cells and neurons. MLD results from an inherited deficiency of arylsulfatase A (ARSA) and myelin degeneration in the central and peripheral nervous systems. Currently, no effective treatment is available for the most frequent late infantile (LI) form of MLD after symptom onset. The LI form results in rapid neurological degradation and early death. ARSA enzyme must be rapidly and efficiently delivered to brain and spinal cord oligodendrocytes of patients with LI MLD in order to potentially stop the progression of the disease. We previously showed that brain gene therapy with adeno-associated virus serotype rh10 (AAVrh10) driving the expression of human ARSA cDNA alleviated most long-term disease manifestations in MLD mice but was not sufficient in MLD patient to improve disease progression. Herein, we evaluated the short-term effects of intravenous AAVPHP.eB delivery driving the expression of human ARSA cDNA under the control of the cytomegalovirus/b-actin hybrid (CAG) promoter in 6-month-old MLD mice that already show marked sulfatide accumulation and brain pathology. Within 3 months, a single intravenous injection of AAVPHP.eB-hARSA-HA resulted in correction of brain and spinal cord sulfatide storage, and improvement of astrogliosis and microgliosis in brain and spinal cord of treated animals. These results strongly support to consider the use of AAVPHP.eB-hARSA vector for intravenous gene therapy in symptomatic rapidly progressing forms of MLD.

Adeno-Associated Viral Vectors for Gene Transfer and Gene Therapy

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
H. Büeler
Keyword(s):  
Gene Expression ◽  
Gene Therapy ◽  
Gene Transfer ◽  
Gene Delivery ◽  
Viral Vectors ◽  
Delivery Systems ◽  
Adeno Associated Virus ◽  
Viral Genes ◽  
Virus Recombinant

AbstractAdeno-associated virus (AAV) is a defective, non-pathogenic human parvovirus that depends for growth on coinfection with a helper adenovirus or herpes virus. Recombinant adeno-associated viruses (rAAVs) have attracted considerable interest as vectors for gene therapy. In contrast to other gene delivery systems, rAAVs lack all viral genes and show long-term gene expression

Sustained phenotypic correction of hemophilia B dogs with a factor IX null mutation by liver-directed gene therapy

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2670-2676 ◽  
Author(s):  
Jane D. Mount ◽  
Roland W. Herzog ◽  
D. Michael Tillson ◽  
Susan A. Goodman ◽  
Nancy Robinson ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Coagulation Factor ◽  
Factor Ix ◽  
Hemophilia B ◽  
Large Animal Model ◽  
Null Mutation ◽  
Large Animal ◽  
Adeno Associated Virus ◽  
Increased Risk

Abstract Hemophilia B is an X-linked coagulopathy caused by absence of functional coagulation factor IX (FIX). Using adeno-associated virus (AAV)–mediated, liver-directed gene therapy, we achieved long-term (> 17 months) substantial correction of canine hemophilia B in 3 of 4 animals, including 2 dogs with an FIX null mutation. This was accomplished with a comparatively low dose of 1 × 1012 vector genomes/kg. Canine FIX (cFIX) levels rose to 5% to 12% of normal, high enough to result in nearly complete phenotypic correction of the disease. Activated clotting times and whole blood clotting times were normalized, activated partial thromboplastin times were substantially reduced, and anti-cFIX was not detected. The fourth animal, also a null mutation dog, showed transient expression (4 weeks), but subsequently developed neutralizing anti-cFIX (inhibitor). Previous work in the canine null mutation model has invariably resulted in inhibitor formation following treatment by either gene or protein replacement therapies. This study demonstrates that hepatic AAV gene transfer can result in sustained therapeutic expression in a large animal model characterized by increased risk of a neutralizing anti-FIX response.

scholarly journals Feasibility of Generating Adeno-Associated Virus Packaging Cell Lines Containing Inducible Adenovirus Helper Genes

2002 ◽  
Vol 76 (4) ◽  
pp. 1904-1913 ◽  
Author(s):  
Chunping Qiao ◽  
Juan Li ◽  
Anna Skold ◽  
Xudong Zhang ◽  
Xiao Xiao
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Cost Effective ◽  
Helper Virus ◽  
Vector System ◽  
Wild Type ◽  
Aav Vector ◽  
Adeno Associated Virus ◽  
Packaging Cell ◽  
Producer Cell

ABSTRACT The adeno-associated virus (AAV) vector system is based on nonpathogenic and helper-virus-dependent parvoviruses. The vector system offers safe, efficient, and long-term in vivo gene transfer in numerous tissues. Clinical trials using AAV vectors have demonstrated vector safety as well as efficiency. The increasing interest in the use of AAV for clinical studies demands large quantities of vectors and hence a need for improvement in vector production. The commonly used transient-transfection method, although versatile and free of adenovirus (Ad), is not cost-effective for large-scale production. While the wild-type-Ad-dependent AAV producer cell lines seem to be cost-effective, this method faces the problem of wild-type Ad contamination. To overcome these shortcomings, we have explored the feasibility of creating inducible AAV packaging cell lines that require neither transfection nor helper virus infection. As a first step toward that goal, we have created a cell line containing highly inducible Ad E1A and E1B genes, which are essential for AAV production. Subsequently, the AAV Rep and Cap genes and an AAV vector containing a green fluorescent protein (GFP) reporter gene were stably introduced into the E1A-E1B cell line, generating inducible AAV-GFP packaging cell lines. Upon induction of E1A and E1B genes and infection with replication-defective Ad with E1A, E1B, and E3 deleted, the packaging cells yielded high-titer AAV-GFP vectors. Finally, the E2, E4, and VA genes of Ad, under the control of their endogenous promoters, were also introduced into these cells. A few producer cell lines were obtained, which could produce AAV-GFP vectors upon simple drug induction. Although future improvement is necessary to increase the stability and vector yield of the cells, our study has nonetheless demonstrated the feasibility of generating helper-virus-free inducible AAV producer cell lines.

scholarly journals Analysis of adeno-associated virus (AAV) wild-type and mutant Rep proteins for their abilities to negatively regulate AAV p5 and p19 mRNA levels.

1994 ◽  
Vol 68 (5) ◽  
pp. 2947-2957 ◽  
Author(s):  
S R Kyöstiö ◽  
R A Owens ◽  
M D Weitzman ◽  
B A Antoni ◽  
N Chejanovsky ◽  
...  
Keyword(s):  
Mrna Levels ◽  
Wild Type ◽  
Adeno Associated Virus ◽  
Rep Proteins

scholarly journals Novel cis-Acting Replication Element in the Adeno-Associated Virus Type 2 Genome Is Involved in Amplification of Integrated rep-cap Sequences

2001 ◽  
Vol 75 (20) ◽  
pp. 9991-9994 ◽  
Author(s):  
Pascale Nony ◽  
Jacques Tessier ◽  
Gilliane Chadeuf ◽  
Peter Ward ◽  
Aurélie Giraud ◽  
...  
Keyword(s):  
Virus Type ◽  
Wild Type ◽  
Adeno Associated Virus ◽  
Cis Acting ◽  
Rep Proteins

ABSTRACT This study identifies a region of the adeno-associated virus type 2 (AAV-2) rep gene (nucleotides 190 to 540 of wild-type AAV-2) as a cis-acting Rep-dependent element able to promote the replication of transiently transfected plasmids. This viral element is also shown to be involved in the amplification of integrated sequences in the presence of adenovirus and Rep proteins.

scholarly journals Long-Term Sustained Effect of Liver-Targeted Adeno-Associated Virus Gene Therapy for Mitochondrial Neurogastrointestinal Encephalomyopathy

2018 ◽  
Vol 29 (6) ◽  
pp. 708-718 ◽  
Author(s):  
Javier Torres-Torronteras ◽  
Raquel Cabrera-Pérez ◽  
Ferran Vila-Julià ◽  
Carlo Viscomi ◽  
Yolanda Cámara ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Adeno Associated Virus ◽  
Mitochondrial Neurogastrointestinal Encephalomyopathy ◽  
Virus Gene ◽  
Sustained Effect
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