scholarly journals Cardiac Gene Therapy: Optimization of Gene Delivery Techniques In Vivo

2010 ◽  
Vol 21 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Michael G. Katz ◽  
JaBaris D. Swain ◽  
Jennifer D. White ◽  
David Low ◽  
Hansell Stedman ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Cardiac Gene ◽  
Delivery Techniques

Exosome as a Natural Gene Delivery Vector for Cancer Treatment

2020 ◽  
Vol 20 (11) ◽  
pp. 821-830
Author(s):  
Prasad Pofali ◽  
Adrita Mondal ◽  
Vaishali Londhe
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Nucleic Acids ◽  
Cancer Treatment ◽  
Intestinal Barrier ◽  
Gene Carrier ◽  
Gene Delivery Vector ◽  
Delivery Vector

Background: Current gene therapy vectors such as viral, non-viral, and bacterial vectors, which are used for cancer treatment, but there are certain safety concerns and stability issues of these conventional vectors. Exosomes are the vesicles of size 40-100 nm secreted from multivesicular bodies into the extracellular environment by most of the cell types in-vivo and in-vitro. As a natural nanocarrier, exosomes are immunologically inert, biocompatible, and can cross biological barriers like the blood-brain barrier, intestinal barrier, and placental barrier. Objective: This review focusses on the role of exosome as a carrier to efficiently deliver a gene for cancer treatment and diagnosis. The methods for loading of nucleic acids onto the exosomes, advantages of exosomes as a smart intercellular shuttle for gene delivery and therapeutic applications as a gene delivery vector for siRNA, miRNA and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and also the limitations of exosomes as a gene carrier are all reviewed in this article. Methods: Mostly, electroporation and chemical transfection are used to prepare gene loaded exosomes. Results: Exosome-mediated delivery is highly promising and advantageous in comparison to the current delivery methods for systemic gene therapy. Targeted exosomes, loaded with therapeutic nucleic acids, can efficiently promote the reduction of tumor proliferation without any adverse effects. Conclusion: In the near future, exosomes can become an efficient gene carrier for delivery and a biomarker for the diagnosis and treatment of cancer.

Abstract MP165: Exosome-mediated Encapsulation Alters AAV Antigenicity and Infectivity: Implications for Gene Delivery in the Heart

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Marta Adamiak ◽  
Yaxuan Liang ◽  
Cherrie Sherman ◽  
Shweta Lodha ◽  
Erik Kohlbrenner ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Cardiac Function ◽  
Neutralizing Antibodies ◽  
Firefly Luciferase ◽  
Interferometric Imaging ◽  
Human Cardiomyocytes ◽  
Clinical Benefits

Gene therapy is a promising approach for the treatment of cardiovascular disease. Current strategies for myocardial gene transfer include the use of adeno-associated virus (AAV) vectors. However, AAVs may not be ideal for gene therapy vectors owing to pre-existing AAV capsid immunity in the human population that may reduce transduction efficacy and hinder preclinical-to-clinical translation. Interestingly, recent studies suggest that exosome-mediated encapsulation may protect viruses from neutralizing antibodies (NAbs) against the capsid and promote viral infectivity. Here, we describe the ability of exosome-enveloped AAVs, i.e. exosomal AAVs (eAAVs), to evade NAbs and serve as a highly efficient gene delivery tool for cardiovascular therapeutics. We have developed a method to purifiy eAAVs from AAV-producing HEK-293T cells, and used electron/confocal microscopy, qPCR, immunoblotting, dynamic light scattering and interferometric imaging measurements to characterize eAAV morphology, contents and mechanism of action. We confirmed eAAVs represent vesicular fractions that exhibit common exosome phenotype, along with the presence of virus particles, and demonstrated that eAAV infectious entry potentially involves trafficking via endocytic compartments. Using flow cytometry, Langendorff perfusion system and bioluminescence imaging, we then evaluated efficiency of heart targeting for eAAV9/eAAV6 and standard AAV9/AAV6 encoding for mCherry or firefly luciferase in human cardiomyocytes in vitro and in mouse model in vivo . Regardless of the presence or absence of NAbs, we showed that eAAVs are more efficient in transduction in the same titer ranges as compared to standard AAVs. To test therapeutic efficacy, we intramyocardially injected eAAV9 or AAV9 vectors encoding for SERCA2a in NAb+ post-myocardial infarction mice and further evaluated cardiac function using echocardiography. Remarkably, eAAV9-SERCA2a outperformed standard AAVs significantly improving cardiac function in the presence of NAbs (%EF 55.14 ± 3.50 compared to 27.31 ± 1.63 at 6 weeks, respectively). In summary, delivery of AAVs protected by carrier exosomes (i.e. eAAVs) may retain the clinical benefits of AAVs while addressing one of its major challenges.

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.

scholarly journals Efficient and Highly Specific Gene Transfer Using Mutated Lentiviral Vectors Redirected with Bispecific Antibodies

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina L. Parker ◽  
Timothy M. Jacobs ◽  
Justin T. Huckaby ◽  
Dimple Harit ◽  
Samuel K. Lai
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Fluorescent Protein ◽  
Ex Vivo ◽  
Endosomal Escape ◽  
Bispecific Antibodies ◽  
Target Cells ◽  
Specific Gene ◽  
Targeted Gene Delivery

ABSTRACT Despite their exceptional potencies, the broad tropism of most commonly used lentivirus (LV) vectors limits their use for targeted gene delivery in vivo. We hypothesized that we could improve the specificity of LV targeting by coupling (i) reduction of their binding to off-target cells with (ii) redirection of the vectors with a bispecific antibody (bsAb) that binds both LV and receptors on target cells. As a proof of concept, we pseudotyped nonreplicating LV using a mutated Sindbis envelope (mSindbis) with ablated binding to native receptors, while retaining the capacity to facilitate efficient fusion and endosomal escape. We then evaluated the transduction potencies of the mSindbis LV for HER2-positive (HER2+) (SKBR3) breast and HER2-negative (HER2−) (A2780) cells when redirected with different bsAbs. mSindbis LV alone failed to induce appreciable green fluorescent protein (GFP) expression in either cell. When mixed with HER2-targeting bsAb, mSindbis LV was exceptionally potent, transducing 12% to 16% of the SKBR3 cells at a multiplicity of infection (MOI [ratio of viral genome copies to target cells]) of 3. Transduction was highly specific, resulting in ∼50-fold-greater selectivity toward SKBR3 cells versus A2780 cells. Redirecting mSindbis LV led to a 10-fold improvement in cell-specific targeting compared to redirecting wild-type Sindbis LV with the same bsAb, underscoring the importance of ablating native virus tropism in order to maximize targeting specificity. The redirection of mutated LV using bsAb represents a potent and highly versatile platform for targeted gene therapy. IMPORTANCE The goal of gene therapy is specific delivery and expression of therapeutic genes to target cells and tissues. Common lentivirus (LV) vectors are efficient gene delivery vehicles but offer little specificity. Here, we report an effective and versatile strategy to redirect LV to target cells using bispecific antibodies (bsAbs) that bind both cell receptors and LV envelope domains. Importantly, we ablated the native receptor binding of LV to minimize off-target transduction. Coupling bsAb specificity and ablated native LV tropism synergistically enhanced the selectivity of our targeted gene delivery system. The modular nature of our bsAb-based redirection enables facile targeting of the same LV to diverse tissues/cells. By abrogating the native broad tropism of LV, our bsAb-LV redirection strategy may enable lentivirus-based gene delivery in vivo, expanding the current use of LV beyond ex vivo applications.

Adeno-associated virus-mediated antiapoptotic gene delivery: in vivo gene therapy for neurological disorders

Methods ◽  
2002 ◽  
Vol 28 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Hideki Mochizuki ◽  
Masauki Miura ◽  
Takashi Shimada ◽  
Yoshikuni Mizuno
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Neurological Disorders ◽  
Adeno Associated Virus ◽  
Antiapoptotic Gene

scholarly journals Optimizations of In Vitro Mucus and Cell Culture Models to Better Predict In Vivo Gene Transfer in Pathological Lung Respiratory Airways: Cystic Fibrosis as an Example

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 47
Author(s):  
Rosy Ghanem ◽  
Véronique Laurent ◽  
Philippe Roquefort ◽  
Tanguy Haute ◽  
Sophie Ramel ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Gene Therapy ◽  
Cell Culture ◽  
Gene Transfer ◽  
Gene Delivery ◽  
Culture Models ◽  
Transfer Strategies ◽  
Cell Culture Models

The respiratory epithelium can be affected by many diseases that could be treated using aerosol gene therapy. Among these, cystic fibrosis (CF) is a lethal inherited disease characterized by airways complications, which determine the life expectancy and the effectiveness of aerosolized treatments. Beside evaluations performed under in vivo settings, cell culture models mimicking in vivo pathophysiological conditions can provide complementary insights into the potential of gene transfer strategies. Such models must consider multiple parameters, following the rationale that proper gene transfer evaluations depend on whether they are performed under experimental conditions close to pathophysiological settings. In addition, the mucus layer, which covers the epithelial cells, constitutes a physical barrier for gene delivery, especially in diseases such as CF. Artificial mucus models featuring physical and biological properties similar to CF mucus allow determining the ability of gene transfer systems to effectively reach the underlying epithelium. In this review, we describe mucus and cellular models relevant for CF aerosol gene therapy, with a particular emphasis on mucus rheology. We strongly believe that combining multiple pathophysiological features in single complex cell culture models could help bridge the gaps between in vitro and in vivo settings, as well as viral and non-viral gene delivery strategies.

Abstract 407: Angiotensin Converting Enzyme 2 (ACE2) Overexpression in Myocytes of Stroke Prone Spontaneously Hypertensive Rats (SHRSP) led to Cardiac Fibrosis

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Rachel Masson ◽  
Stuart A Nicklin ◽  
Lorraine M Work ◽  
Kirsten Gilday ◽  
Paul Gregorevic ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Gene Transfer ◽  
Gene Delivery ◽  
Cardiac Fibrosis ◽  
Heart Function ◽  
Cardiac Structure ◽  
Cardiac Gene ◽  
Picrosirius Red

Aim: Assess the effect of ACE2 overexpression in vivo on heart function and blood pressure. Identify an efficient cardiac gene delivery vector by comparison and optimisation of adeno-associated virus 6 (AAV6) and AAV9 mediated gene delivery to myocardium in vivo in SHRSPs. Methods: We administered a single intravenous injection of AAV6CMVlacZ or AAV9CMVlacZ at 3 doses (2x10 11 , 1.5x10 12 and 3x10 12 vp/rat) into 6 week old SHRSP. Animals were sacrificed 14 days post delivery and tissues stained for β-galactosidase (β-gal) expression which was confirmed by immunohistochemistry (IHC). Quantitative PCR compared the presence of lacZ containing genomes between tissues and animals. To assess the effect of ACE2 overexpression in SHRSP, 4 groups of animals (n = 6/group) were included in the study; PBS, Enalapril, AAV6-alkaline phosphatase (control reporter gene) and AAV6-ACE2. Blood pressure was monitored by tail cuff and cardiac function assessed by echocardiography (ECHO). Cardiac structure was assessed by haematoxylin and eosin (H&E) staining and cardiac fibrosis evaluated by Masson’s trichrome and picrosirius red. Results: AAV6-mediated gene transfer was high in heart and skeletal muscle and a dose-dependent response was observed. β-gal staining and IHC confirmed transgene expression throughout the musculature but not within other tissues (kidney, liver, spleen and lung). Whilst AAV9 mediated approximately 10 fold (for highest dose) less gene transfer to the heart than AAV6, levels were comparable in skeletal muscle. However, the AAV9 vector accumulated in the kidneys. ACE2 was overexpressed selectively in the AAV6-ACE2-injected animals. ECHO showed substantial systolic dysfunction in ACE2-injected SHRSP’s compared to controls, and H&E revealed abnormal cardiac structure. Masson’s trichrome and picrosirius red indicated severe cardiac fibrosis. Blood pressure was significantly lower (p<0.001) in the ACE2 group in weeks 9, 10 and 11 post infusion compared to PBS and control vector infused animals. Conclusions: AAV6 exhibited a more favourable profile for cardiac gene delivery than AAV9, and represents a useful tool for studying mechanisms of cardiovascular disease. Overexpression of ACE2 in SHRSP myocardium led to severe cardiac fibrosis.

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