scholarly journals Weighing the DNA content of Adeno-Associated Virus vectors with zeptogram precision using nanomechanical resonators

2021 ◽  
Author(s):  
Georgios Katsikis ◽  
Iris E Hwang ◽  
Wade Wang ◽  
Vikas S Bhat ◽  
Nicole L McIntosh ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Quality Control ◽  
Viral Vectors ◽  
Analytical Ultracentrifugation ◽  
Vaccine Development ◽  
Turnaround Time ◽  
Charge Detection ◽  
Adeno Associated Virus ◽  
Nanomechanical Resonators

Quantifying the composition of viral vectors used in vaccine development and gene therapy is critical for assessing their functionality. Adeno-Associated Virus (AAV) vectors, which are the most widely used viral vectors for in-vivo gene therapy, are typically characterized using PCR, ELISA, and Analytical Ultracentrifugation which require laborious protocols or hours of turnaround time. Emerging methods such as Charge-Detection Mass Spectroscopy, Static Light Scattering, and Mass Photometry offer turnaround times of minutes for measuring AAV mass, but mostly require purified AAV-based reference materials for calibration. Here, we demonstrate a method for using Suspended Nanomechanical Resonators (SNR) to directly measure both AAV mass and aggregation from a few microliters of sample within minutes. We achieve a resolution near 10 zeptograms which corresponds to 1% of the genome holding capacity of the AAV capsid. Our results show the potential of our method for providing real-time quality control of viral vectors during biomanufacturing.

scholarly journals Riboswitches for Controlled Expression of Therapeutic Transgenes Delivered by Adeno-Associated Viral Vectors

2021 ◽  
Vol 14 (6) ◽  
pp. 554
Author(s):  
Zachary J. Tickner ◽  
Michael Farzan
Keyword(s):  
Gene Therapy ◽  
Animal Models ◽  
Mammalian Cells ◽  
Viral Vectors ◽  
Adeno Associated Virus ◽  
Gene Therapies ◽  
Expression Control ◽  
Transgene Delivery ◽  
Improved Performance

Vectors developed from adeno-associated virus (AAV) are powerful tools for in vivo transgene delivery in both humans and animal models, and several AAV-delivered gene therapies are currently approved for clinical use. However, AAV-mediated gene therapy still faces several challenges, including limited vector packaging capacity and the need for a safe, effective method for controlling transgene expression during and after delivery. Riboswitches, RNA elements which control gene expression in response to ligand binding, are attractive candidates for regulating expression of AAV-delivered transgene therapeutics because of their small genomic footprints and non-immunogenicity compared to protein-based expression control systems. In addition, the ligand-sensing aptamer domains of many riboswitches can be exchanged in a modular fashion to allow regulation by a variety of small molecules, proteins, and oligonucleotides. Riboswitches have been used to regulate AAV-delivered transgene therapeutics in animal models, and recently developed screening and selection methods allow rapid isolation of riboswitches with novel ligands and improved performance in mammalian cells. This review discusses the advantages of riboswitches in the context of AAV-delivered gene therapy, the subsets of riboswitch mechanisms which have been shown to function in human cells and animal models, recent progress in riboswitch isolation and optimization, and several examples of AAV-delivered therapeutic systems which might be improved by riboswitch regulation.

Non-Viral Vectors for Gene Delivery

2018 ◽  
Vol 9 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Aparna Bansal ◽  
Himanshu
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Expression System ◽  
Target Cells ◽  
Specific Expression ◽  
Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

scholarly journals Pseudotyping Lentiviral Vectors: When the Clothes Make the Virus

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1311 ◽  
Author(s):  
Alexis Duvergé ◽  
Matteo Negroni
Keyword(s):  
Gene Therapy ◽  
Genetic Modification ◽  
Viral Vectors ◽  
Molecular Level ◽  
Lentiviral Vectors ◽  
Human Cells ◽  
Surface Proteins ◽  
Holy Grail ◽  
Viral Therapy

Delivering transgenes to human cells through transduction with viral vectors constitutes one of the most encouraging approaches in gene therapy. Lentivirus-derived vectors are among the most promising vectors for these approaches. When the genetic modification of the cell must be performed in vivo, efficient specific transduction of the cell targets of the therapy in the absence of off-targeting constitutes the Holy Grail of gene therapy. For viral therapy, this is largely determined by the characteristics of the surface proteins carried by the vector. In this regard, an important property of lentiviral vectors is the possibility of being pseudotyped by envelopes of other viruses, widening the panel of proteins with which they can be armed. Here, we discuss how this is achieved at the molecular level and what the properties and the potentialities of the different envelope proteins that can be used for pseudotyping these vectors are.

In Vivo Potency Assay for Adeno-Associated Virus–Based Gene Therapy Vectors Using AAVrh.10 as an Example

2018 ◽  
Vol 29 (3) ◽  
pp. 146-155 ◽  
Author(s):  
Bishnu P. De ◽  
Alvin Chen ◽  
Christiana O. Salami ◽  
Benjamin Van de Graaf ◽  
Jonathan B. Rosenberg ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Potency Assay ◽  
Adeno Associated Virus ◽  
Gene Therapy Vectors

Gene therapy for critical limb ischemia: Per aspera ad astra

2021 ◽  
Vol 21 ◽  
Author(s):  
Vyacheslav Z. Tarantul ◽  
Alexander V. Gavrilenko
Keyword(s):  
Gene Therapy ◽  
Critical Limb Ischemia ◽  
Viral Vectors ◽  
Ex Vivo ◽  
Single Gene ◽  
Public Health Problem ◽  
Limb Ischemia ◽  
Therapeutic Angiogenesis ◽  
Effective Treatment Option

: Peripheral artery diseases remain a serious public health problem. Although there are many traditional methods for their treatment using conservative therapeutic techniques and surgery, gene therapy is an alternative and potentially more effective treatment option especially for “no option” patients. This review treats the results of many years of research and application of gene therapy as an example of treatment of patients with critical limb ischemia. Data on successful and unsuccessful attempts to use this technology for treating this disease are presented. Trends in changing the paradigm of approaches to therapeutic angiogenesis are noted: from viral vectors to non-viral vectors, from gene transfer to the whole organism to targeted transfer to cells and tissues, from single gene use to combination of genes; from DNA therapy to RNA therapy, from in vivo therapy to ex vivo therapy.

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

scholarly journals Nanotechnology and adeno-associated virus-based decorin gene therapy ameliorates peritoneal fibrosis

2014 ◽  
Vol 307 (7) ◽  
pp. F777-F782 ◽  
Author(s):  
Kunal Chaudhary ◽  
Harold Moore ◽  
Ashish Tandon ◽  
Suneel Gupta ◽  
Ramesh Khanna ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mesothelial Cell ◽  
Peritoneal Fibrosis ◽  
Tissue Samples ◽  
Adeno Associated Virus ◽  
Peritoneal Tissue ◽  
Stage Renal Disease

Peritoneal dialysis (PD) is a life-sustaining therapy for end-stage renal disease (ESRD), used by 10–15% of the dialysis population worldwide. Peritoneal fibrosis (PF) is a known complication of long-term PD and frequently follows episodes of peritonitis, rendering the peritoneal membrane inadequate for dialysis. Transforming growth factor (TGF)-β is an inducer of fibrosis in several tissues and organs, and its overexpression has been correlated with PF. Animal models of peritonitis have shown an increase in expression of TGF-β in the peritoneal tissue. Decorin, a proteoglycan and component of the extracellular matrix, inactivates TGF-β, consequently reducing fibrosis in many tissues. Recently, gold nanoparticles (GNP) have been used for drug delivery in a variety of settings. In the present study, we tested the possibility that GNP-delivered decorin gene therapy ameliorates zymosan-mediated PF. We created a PF model using zymosan-induced peritonitis. Rats were treated with no decorin, GNP-decorin, or adeno-associated virus-decorin (AAV-decorin) and compared with controls. Tissue samples were then stained for Masson's trichrome, enface silver, and hematoxylin and eosin, and immunohistochemistry was carried out with antibodies to TGF-β1, α-smooth muscle actin (α-SMA), and VEGF. Animals which were treated with GNP-decorin and AAV-decorin gene therapy had significant reductions in PF compared with untreated animals. Compared with untreated animals, the treated animals had better preserved peritoneal mesothelial cell size, a significant decrease in peritoneal thickness, and decreased α-SMA. Quantitative PCR measurements showed a significant decrease in the peritoneal tissue levels of α-SMA, TGF-β, and VEGF in treated vs. untreated animals. This study shows that both GNP-delivered and AAV-mediated decorin gene therapies significantly decrease PF in vivo in a rodent model. This approach has important clinical translational potential in providing a therapeutic strategy to prevent PF in PD patients.

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

2006 ◽  
Vol 80 (19) ◽  
pp. 9831-9836 ◽  
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.

scholarly journals Identification and Validation of Small Molecules That Enhance Recombinant Adeno-associated Virus Transduction following High-Throughput Screens

2016 ◽  
Vol 90 (16) ◽  
pp. 7019-7031 ◽  
Author(s):  
Sarah C. Nicolson ◽  
Chengwen Li ◽  
Matthew L. Hirsch ◽  
Vincent Setola ◽  
R. Jude Samulski
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
High Throughput ◽  
Adeno Associated Virus ◽  
Virus Gene ◽  
Diploid Cells ◽  
High Throughput Screens ◽  
Group 1

ABSTRACTWhile the recent success of adeno-associated virus (AAV)-mediated gene therapy in clinical trials is promising, challenges still face the widespread applicability of recombinant AAV(rAAV). A major goal is to enhance the transduction efficiency of vectors in order to achieve therapeutic levels of gene expression at a vector dose that is below the immunological response threshold. In an attempt to identify novel compounds that enhance rAAV transduction, we performed two high-throughput screens comprising 2,396 compounds. We identified 13 compounds that were capable of enhancing transduction, of which 12 demonstrated vector-specific effects and 1 could also enhance vector-independent transgene expression. Many of these compounds had similar properties and could be categorized into five groups: epipodophyllotoxins (group 1), inducers of DNA damage (group 2), effectors of epigenetic modification (group 3), anthracyclines (group 4), and proteasome inhibitors (group 5). We optimized dosing for the identified compounds in several immortalized human cell lines as well as normal diploid cells. We found that the group 1 epipodophyllotoxins (teniposide and etoposide) consistently produced the greatest transduction enhancement. We also explored transduction enhancement among single-stranded, self-complementary, and fragment vectors and found that the compounds could impact fragmented rAAV2 transduction to an even greater extent than single-stranded vectors.In vivoanalysis of rAAV2 and all of the clinically relevant compounds revealed that, consistent with ourin vitroresults, teniposide exhibited the greatest level of transduction enhancement. Finally, we explored the capability of teniposide to enhance transduction of fragment vectorsin vivousing an AAV8 capsid that is known to exhibit robust liver tropism. Consistent with ourin vitroresults, teniposide coadministration greatly enhanced fragmented rAAV8 transduction at 48 h and 8 days. This study provides a foundation based on the rAAV small-molecule screen methodology, which is ideally used for more-diverse libraries of compounds that can be tested for potentiating rAAV transduction.IMPORTANCEThis study seeks to enhance the capability of adeno-associated viral vectors for therapeutic gene delivery applicable to the treatment of diverse diseases. To do this, a comprehensive panel of FDA-approved drugs were tested in human cells and in animal models to determine if they increased adeno-associated virus gene delivery. The results demonstrate that particular groups of drugs enhance adeno-associated virus gene delivery by unknown mechanisms. In particular, the enhancement of gene delivery was approximately 50 to 100 times better with than without teniposide, a compound that is also used as chemotherapy for cancer. Collectively, these results highlight the potential for FDA-approved drug enhancement of adeno-associated virus gene therapy, which could result in safe and effective treatments for diverse acquired or genetic diseases.

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