Human Gene Therapy in Gastrointestinal Diseases: In Vivo and In Vitro Approaches

ABSTRACT Although the adeno-associated virus type 2 (AAV)-based vector system has gained attention as a potentially useful alternative to the more commonly used retroviral and adenoviral vectors for human gene therapy, the single-stranded nature of the viral genome, and consequently the rate-limiting second-strand viral DNA synthesis, significantly affect its transduction efficiency. We have identified a cellular tyrosine phosphoprotein, designated the single-stranded D sequence-binding protein (ssD-BP), which interacts specifically with the D sequence at the 3′ end of the AAV genome and may prevent viral second-strand DNA synthesis in HeLa cells (K. Y. Qing et al., Proc. Natl. Acad. Sci. USA 94:10879–10884, 1997). In the present studies, we examined whether the phosphorylation state of the ssD-BP correlates with the ability of AAV to transduce various established and primary cells in vitro and murine tissues in vivo. The efficiencies of transduction of established human cells by a recombinant AAV vector containing the β-galactosidase reporter gene were 293 > KB > HeLa, which did not correlate with the levels of AAV infectivity. However, the amounts of dephosphorylated ssD-BP which interacted with the minus-strand D probe were also as follows: 293 > KB > HeLa. Predominantly the phosphorylated form of the ssD-BP was detected in cells of the K562 line, a human erythroleukemia cell line, and in CD34+ primary human hematopoietic progenitor cells; consequently, the efficiencies of AAV-mediated transgene expression were significantly lower in these cells. Murine Sca-1+ lin − primary hematopoietic stem/progenitor cells contained predominantly the dephosphorylated form of the ssD-BP, and these cells could be efficiently transduced by AAV vectors. Dephosphorylation of the ssD-BP also correlated with expression of the adenovirus E4orf6 protein, known to induce AAV gene expression. A deletion mutation in the E4orf6 gene resulted in a failure to catalyze dephosphorylation of the ssD-BP. Extracts prepared from mouse brain, heart, liver, lung, and skeletal-muscle tissues, all of which are known to be highly permissive for AAV-mediated transgene expression, contained predominantly the dephosphorylated form of the ssD-BP. Thus, the efficiency of transduction by AAV vectors correlates well with the extent of the dephosphorylation state of the ssD-BP in vitro as well as in vivo. These data suggest that further studies on the cellular gene that encodes the ssD-BP may promote the successful use of AAV vectors in human gene therapy.

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Genome Editing Technologies: From Bench Side to Bedside

Acta Medica ◽

10.32552/2018.actamedica.282 ◽

2018 ◽

Vol 49 (3) ◽

pp. 30

Author(s):

Fulya Yaylacıoğlu Tuncay ◽

Pervin Rukiye Dinçer

Keyword(s):

Gene Therapy ◽

Animal Models ◽

Genome Editing ◽

Clinical Studies ◽

Human Gene ◽

Human Gene Therapy ◽

Novel Technologies ◽

Preclinical And Clinical Studies

The development of genome editing technologies has given the chance to researchers to manipulate any genomic sequences precisely. This ability is very useful for creating animal models to study human diseases in vivo; for easy creation of isogenic cell lines to study in vitro and most importantly for overcoming many disadvantages that the researchers faced during the human gene therapy trials. Here we review the basic mechanisms of genome editing technology and the four genome-editing platforms. We also discuss the applications of these novel technologies in preclinical and clinical studies in four groups according to the mechanism used, and lastly, summarize the problems in these technologies.

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Adeno-Associated Virus Type 2-Mediated Gene Transfer: Role of Cellular FKBP52 Protein in Transgene Expression

Journal of Virology ◽

10.1128/jvi.75.19.8968-8976.2001 ◽

2001 ◽

Vol 75 (19) ◽

pp. 8968-8976 ◽

Cited By ~ 96

Author(s):

Keyun Qing ◽

Jonathan Hansen ◽

Kirsten A. Weigel-Kelley ◽

Mengqun Tan ◽

Shangzhen Zhou ◽

...

Keyword(s):

Gene Therapy ◽

Dna Synthesis ◽

Transgene Expression ◽

Human Gene ◽

Transduction Efficiency ◽

Adeno Associated Virus ◽

Human Gene Therapy

ABSTRACT Although adeno-associated virus type 2 (AAV) has gained attention as a potentially useful vector for human gene therapy, the transduction efficiencies of AAV vectors vary greatly in different cells and tissues in vitro and in vivo. We have documented that a cellular tyrosine phosphoprotein, designated the single-stranded D-sequence-binding protein (ssD-BP), plays a crucial role in AAV-mediated transgene expression (K. Y. Qing, X.-S. Wang, D. M. Kube, S. Ponnazhagan, A. Bajpai, and A. Srivastava, Proc. Natl. Acad. Sci. USA 94:10879–10884, 1997). We have documented a strong correlation between the phosphorylation state of ssD-BP and AAV transduction efficiency in vitro as well as in vivo (K. Y. Qing, B. Khuntrirat, C. Mah, D. M. Kube, X.-S. Wang, S. Ponnazhagan, S. Z. Zhou, V. J. Dwarki, M. C. Yoder, and A. Srivastava, J. Virol. 72:1593–1599, 1998). We have also established that the ssD-BP is phosphorylated by epidermal growth factor receptor protein tyrosine kinase and that the tyrosine-phosphorylated form, but not the dephosphorylated form, of ssD-BP prevents AAV second-strand DNA synthesis and, consequently, results in a significant inhibition of AAV-mediated transgene expression (C. Mah, K. Y. Qing, B. Khuntrirat, S. Ponnazhagan, X.-S. Wang, D. M. Kube, M. C. Yoder, and A. Srivastava, J. Virol. 72:9835–9841, 1998). Here, we report that a partial amino acid sequence of ssD-BP purified from HeLa cells is identical to a portion of a cellular protein that binds the immunosuppressant drug FK506, termed the FK506-binding protein 52 (FKBP52). FKBP52 was purified by using a prokaryotic expression plasmid containing the human cDNA. The purified protein could be phosphorylated at both tyrosine and serine or threonine residues, and only the phosphorylated forms of FKBP52 were shown to interact with the AAV single-stranded D-sequence probe. Furthermore, in in vitro DNA replication assays, tyrosine-phosphorylated FKBP52 inhibited AAV second-strand DNA synthesis by greater than 90%. Serine- or threonine-phosphorylated FKBP52 caused ≈40% inhibition, whereas dephosphorylated FKBP52 had no effect on AAV second-strand DNA synthesis. Deliberate overexpression of FKBP52 effectively reduced the extent of tyrosine phosphorylation of the protein, resulting in a significant increase in AAV-mediated transgene expression in human and murine cell lines. These studies corroborate the idea that the phosphorylation status of the cellular FKBP52 protein correlates strongly with AAV transduction efficiency, which may have important implications for the optimal use of AAV vectors in human gene therapy.

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Enhanced Transgene Expression from Recombinant Single-Stranded D-Sequence-Substituted Adeno-Associated Virus Vectors in Human Cell LinesIn Vitroand in Murine HepatocytesIn Vivo

Journal of Virology ◽

10.1128/jvi.02581-14 ◽

2014 ◽

Vol 89 (2) ◽

pp. 952-961 ◽

Cited By ~ 21

Author(s):

Chen Ling ◽

Yuan Wang ◽

Yuan Lu ◽

Lina Wang ◽

Giridhara R. Jayandharan ◽

...

Keyword(s):

Gene Therapy ◽

Human Cell ◽

Transgene Expression ◽

Human Gene ◽

Adeno Associated Virus ◽

Human Virus ◽

Human Gene Therapy ◽

Virus Serotype

ABSTRACTWe have previously reported that the removal of a 20-nucleotide sequence, termed the D sequence, from both ends of the inverted terminal repeats (ITRs) in the adeno-associated virus serotype 2 (AAV2) genome significantly impairs rescue, replication, and encapsidation of the viral genomes (X. S. Wang, S. Ponnazhagan, and A. Srivastava, J Mol Biol 250:573–580, 1995; X. S. Wang, S. Ponnazhagan, and A. Srivastava, J Virol 70:1668–1677, 1996). Here we describe that replacement of only one D sequence in either ITR restores each of these functions, but DNA strands of only single polarity are encapsidated in mature progeny virions. Since most commonly used recombinant AAV vectors contain a single-stranded DNA (ssDNA), which is transcriptionally inactive, efficient transgene expression from AAV vectors is dependent upon viral second-strand DNA synthesis. We have also identified a transcription suppressor sequence in one of the D sequences, which shares homology with the binding site for the cellular NF-κB-repressing factor (NRF). The removal of this D sequence from, and replacement with a sequence containing putative binding sites for transcription factors in, single-stranded AAV (ssAAV) vectors significantly augments transgene expression both in human cell linesin vitroand in murine hepatocytesin vivo. The development of these genome-modified ssAAV vectors has implications not only for the basic biology of AAV but also for the optimal use of these vectors in human gene therapy.IMPORTANCEThe results of the studies described here not only have provided novel insights into some of the critical steps in the life cycle of a human virus, the adeno-associated virus (AAV), that causes no known disease but have also led to the development of novel recombinant AAV vectors which are more efficient in allowing increased levels of gene expression. Thus, these studies have significant implications for the potential use of these novel AAV vectors in human gene therapy.

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Activation of p38 and ERK Signaling during Adenovirus Vector Cell Entry Lead to Expression of the C-X-C Chemokine IP-10

Journal of Virology ◽

10.1128/jvi.76.4.1559-1568.2002 ◽

2002 ◽

Vol 76 (4) ◽

pp. 1559-1568 ◽

Cited By ~ 90

Author(s):

Lee Anne Tibbles ◽

Jason C. L. Spurrell ◽

Gloria P. Bowen ◽

Qiang Liu ◽

Mindy Lam ◽

...

Keyword(s):

Gene Therapy ◽

Mrna Expression ◽

Inflammatory Responses ◽

Human Gene ◽

Adenovirus Vector ◽

Endosomal Escape ◽

Human Gene Therapy ◽

Serotype 5 ◽

Adenovirus Vectors

ABSTRACT The use of adenovirus vectors for human gene therapy is limited by potent inflammatory responses that result in significant morbidity. In kidney-derived epithelial cells (REC), activation of extracellular signal-regulated kinase 1/2 (ERK) and p38 kinase (p38) pathways occurred within 20 min of transduction with the serotype 5 adenovirus vector AdCMVβgal. Inhibition of ERK and p38 with U0126 and SB203580, respectively, reduced the expression of IP-10 mRNA following transduction with AdCMVβgal. To determine the role of the coxsackievirus-adenovirus receptor (CAR) or αv integrins in the activation of ERK and p38 and the expression of IP-10, REC cells were transduced with the fiber-modified and RGD-deleted adenovirus vectors AdL.F(RAEK-HA) and AdL.PB(HA), respectively. Compared with the wild-type capsid vector Ad5Luc, transduction with AdL.F(RAEK-HA) and AdL.PB(HA) resulted in reduced ERK-p38 activation and less IP-10 mRNA expression. The decreased IP-10 expression induced by the tropism-modified vectors was due to diminished transduction, since increasing multiplicity of infection resulted in increased IP-10 expression. Inhibition of adenovirus penetration with bafilomycin A1 or ammonium chloride attenuated the activation of ERK-p38 and IP-10 mRNA expression following infection, suggesting that endosomal escape was required to trigger these pathways. In vivo, direct inhibition of ERK and p38 signaling pathways inhibited adenovirus vector-induced IP-10 expression in mouse liver 1 h following transduction. These results demonstrate the importance of signaling via ERK and p38 in the early host response to adenovirus vectors and will permit the development of novel strategies to improve the safety and efficacy of these agents in human gene therapy.

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The 37/67-Kilodalton Laminin Receptor Is a Receptor for Adeno-Associated Virus Serotypes 8, 2, 3, and 9

Journal of Virology ◽

10.1128/jvi.00878-06 ◽

2006 ◽

Vol 80 (19) ◽

pp. 9831-9836 ◽

Cited By ~ 264

Author(s):

Bassel Akache ◽

Dirk Grimm ◽

Kusum Pandey ◽

Stephen R. Yant ◽

Hui Xu ◽

...

Keyword(s):

Gene Therapy ◽

Cultured Cells ◽

Human Gene ◽

Laminin Receptor ◽

Transduction Efficiency ◽

Adeno Associated Virus ◽

Virus Serotype ◽

Tumor Gene

ABSTRACT Adeno-associated virus serotype 8 (AAV8) is currently emerging as a powerful gene transfer vector, owing to its capability to efficiently transduce many different tissues in vivo. While this is believed to be in part due to its ability to uncoat more readily than other AAV serotypes such as AAV2, understanding all the processes behind AAV8 transduction is important for its application and optimal use in human gene therapy. Here, we provide the first report of a cellular receptor for AAV8, the 37/67-kDa laminin receptor (LamR). We document binding of LamR to AAV8 capsid proteins and intact virions in vitro and demonstrate its contribution to AAV8 transduction of cultured cells and mouse liver in vivo. We also show that LamR plays a role in transduction by three other closely related serotypes (AAV2, -3, and -9). Sequence and deletion analysis allowed us to map LamR binding to two protein subdomains predicted to be exposed on the AAV capsid exterior. Use of LamR, which is constitutively expressed in many clinically relevant tissues and is overexpressed in numerous cancers, provides a molecular explanation for AAV8's broad tissue tropism. Along with its robust transduction efficiency, our findings support the continued development of AAV8-based vectors for clinical applications in humans, especially for tumor gene therapy.

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Human Gene Therapy for Malignant Gliomas (Glioblastoma Multiforme and Anaplastic Astrocytoma) by In Vivo Transduction with Human Interferon β Gene Using Cationic Liposomes

Human Gene Therapy ◽

10.1089/10430340460732472 ◽

2004 ◽

Vol 15 (1) ◽

pp. 77-86 ◽

Cited By ~ 91

Author(s):

Jun Yoshida ◽

Masaaki Mizuno ◽

Masazumi Fujii ◽

Yasukazu Kajita ◽

Norimoto Nakahara ◽

...

Keyword(s):

Gene Therapy ◽

Glioblastoma Multiforme ◽

Anaplastic Astrocytoma ◽

Human Gene ◽

Malignant Gliomas ◽

Cationic Liposomes ◽

Human Interferon ◽

Interferon Β ◽

Human Gene Therapy

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In Vitro and In Vivo Gene Therapy Vector Evolution via Multispecies Interbreeding and Retargeting of Adeno-Associated Viruses

Journal of Virology ◽

10.1128/jvi.00254-08 ◽

2008 ◽

Vol 82 (12) ◽

pp. 5887-5911 ◽

Cited By ~ 331

Author(s):

Dirk Grimm ◽

Joyce S. Lee ◽

Lora Wang ◽

Tushar Desai ◽

Bassel Akache ◽

...

Keyword(s):

Gene Therapy ◽

Human Gene ◽

Single Type ◽

Alveolar Cells ◽

Human Gene Therapy ◽

Viral Peptide ◽

Peptide Display ◽

Family Shuffling

ABSTRACT Adeno-associated virus (AAV) serotypes differ broadly in transduction efficacies and tissue tropisms and thus hold enormous potential as vectors for human gene therapy. In reality, however, their use in patients is restricted by prevalent anti-AAV immunity or by their inadequate performance in specific targets, exemplified by the AAV type 2 (AAV-2) prototype in the liver. Here, we attempted to merge desirable qualities of multiple natural AAV isolates by an adapted DNA family shuffling technology to create a complex library of hybrid capsids from eight different wild-type viruses. Selection on primary or transformed human hepatocytes yielded pools of hybrids from five of the starting serotypes: 2, 4, 5, 8, and 9. More stringent selection with pooled human antisera (intravenous immunoglobulin [IVIG]) then led to the selection of a single type 2/type 8/type 9 chimera, AAV-DJ, distinguished from its closest natural relative (AAV-2) by 60 capsid amino acids. Recombinant AAV-DJ vectors outperformed eight standard AAV serotypes in culture and greatly surpassed AAV-2 in livers of naïve and IVIG-immunized mice. A heparin binding domain in AAV-DJ was found to limit biodistribution to the liver (and a few other tissues) and to affect vector dose response and antibody neutralization. Moreover, we report the first successful in vivo biopanning of AAV capsids by using a new AAV-DJ-derived viral peptide display library. Two peptides enriched after serial passaging in mouse lungs mediated the retargeting of AAV-DJ vectors to distinct alveolar cells. Our study validates DNA family shuffling and viral peptide display as two powerful and compatible approaches to the molecular evolution of novel AAV vectors for human gene therapy applications.

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The FACT Complex Promotes Avian Leukosis Virus DNA Integration

Journal of Virology ◽

10.1128/jvi.00082-17 ◽

2017 ◽

Vol 91 (7) ◽

Cited By ~ 10

Author(s):

Shelby Winans ◽

Ross C. Larue ◽

Carly M. Abraham ◽

Nikolozi Shkriabai ◽

Amelie Skopp ◽

...

Keyword(s):

Gene Therapy ◽

Insertional Mutagenesis ◽

Human Gene ◽

Leukemia Virus ◽

Avian Leukosis Virus ◽

Human Gene Therapy ◽

Cellular Expression ◽

Substantial Risk ◽

Infected Cells

ABSTRACT All retroviruses need to integrate a DNA copy of their genome into the host chromatin. Cellular proteins regulating and targeting lentiviral and gammaretroviral integration in infected cells have been discovered, but the factors that mediate alpharetroviral avian leukosis virus (ALV) integration are unknown. In this study, we have identified the FACT protein complex, which consists of SSRP1 and Spt16, as a principal cellular binding partner of ALV integrase (IN). Biochemical experiments with purified recombinant proteins show that SSRP1 and Spt16 are able to individually bind ALV IN, but only the FACT complex effectively stimulates ALV integration activity in vitro. Likewise, in infected cells, the FACT complex promotes ALV integration activity, with proviral integration frequency varying directly with cellular expression levels of the FACT complex. An increase in 2-long-terminal-repeat (2-LTR) circles in the depleted FACT complex cell line indicates that this complex regulates the ALV life cycle at the level of integration. This regulation is shown to be specific to ALV, as disruption of the FACT complex did not inhibit either lentiviral or gammaretroviral integration in infected cells. IMPORTANCE The majority of human gene therapy approaches utilize HIV-1- or murine leukemia virus (MLV)-based vectors, which preferentially integrate near genes and regulatory regions; thus, insertional mutagenesis is a substantial risk. In contrast, ALV integrates more randomly throughout the genome, which decreases the risks of deleterious integration. Understanding how ALV integration is regulated could facilitate the development of ALV-based vectors for use in human gene therapy. Here we show that the FACT complex directly binds and regulates ALV integration efficiency in vitro and in infected cells.

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