scholarly journals Macrophage Depletion via Clodronate Pretreatment Reduces Transgene Expression from AAV Vectors In Vivo

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2002 ◽  
Author(s):  
Darrick L. Yu ◽  
Natalie S. M. Chow ◽  
Byram W. Bridle ◽  
Sarah K. Wootton

Adeno-associated virus is a popular gene delivery vehicle for gene therapy studies. A potential roadblock to widespread clinical adoption is the high vector doses required for efficient transduction in vivo, and the potential for subsequent immune responses that may limit prolonged transgene expression. We hypothesized that the depletion of macrophages via systemic delivery of liposome-encapsulated clodronate would improve transgene expression if given prior to systemic AAV vector administration, as has been shown to be the case with adenoviral vectors. Contrary to our expectations, clodronate liposome pretreatment resulted in significantly reduced transgene expression in the liver and heart, but permitted moderate transduction of the white pulp of the spleen. There was a remarkable localization of transgene expression from the red pulp to the center of the white pulp in clodronate-treated mice compared to untreated mice. Similarly, a greater proportion of transgene expression could be observed in the medulla located in the center of the lymph node in mice treated with clodronate-containing liposomes as compared to untreated mice where transgene expression was localized primarily to the cortex. These results underscore the highly significant role that the immune system plays in influencing the distribution and relative numbers of transduced cells in the context of AAV-mediated gene delivery.

2007 ◽  
Vol 81 (22) ◽  
pp. 12360-12367 ◽  
Author(s):  
Stephanie G. Sumner-Jones ◽  
Deborah R. Gill ◽  
Stephen C. Hyde

ABSTRACT While recombinant adeno-associated virus (rAAV) vectors promote long-term transgene expression in the lungs and other organs, the goal of correcting chronic inherited lung diseases such as cystic fibrosis with this type of viral gene transfer vector is limited by the requirement of achieving stable potent transgene expression, potentially requiring vector readministration. Here we evaluated the abilities of rAAV type 5/5 (rAAV5/5) vectors based on the genome and capsid of AAV5 to efficiently transduce the lungs and nasal epithelium of mice after repeated administration. Transduction efficiency as judged by reporter gene expression was markedly reduced on a second rAAV5/5 administration and effectively abolished on a third. Varying the period between administrations from 8 to 36 weeks did not allow efficient repeated administration. A rapid rise in anti-AAV5 antibodies was noted after rAAV5/5 vector administration that was sustained for the entire period of investigation (in some cases exceeding 9 months). Furthermore, this antibody response and subsequent failure to repeatedly administer the vector were not rescued by the in vivo expression of CTLA4Ig from an rAAV5/5 vector. These results suggest that without the development of an effective and clinically acceptable immunosuppression strategy, treatments for chronic diseases that require repeated administration of rAAV5/5 vectors will be unsuccessful.


2016 ◽  
Vol 90 (16) ◽  
pp. 7019-7031 ◽  
Author(s):  
Sarah C. Nicolson ◽  
Chengwen Li ◽  
Matthew L. Hirsch ◽  
Vincent Setola ◽  
R. Jude Samulski

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.


2008 ◽  
Vol 83 (4) ◽  
pp. 2004-2010 ◽  
Author(s):  
M. Puntel ◽  
R. J. Barrett ◽  
S. Mondkar ◽  
V. Saxena ◽  
K. M. Kroeger ◽  
...  

ABSTRACT Increased transgene expression per vector genome is an important goal in the optimization of viral vectors for gene therapy. Herein we demonstrate that herpes simplex virus type 1 (HSV1) thymidine kinase (TK) gene sequences (1,131 bp) fused to the 3′ end of lacZ increase transgene expression from high-capacity adenoviral vectors (HCAd), but not from first-generation (Ad) vectors. The woodchuck hepatitis virus posttranscriptional regulatory element (WPRE), in contrast, increased transgene expression levels from Ad but not HCAd vectors. The differential activity of the HSV1 TK gene and WPRE sequences was detected both in vitro and in vivo and suggests potentially different mechanisms of action or the interaction of these elements with vector genomic sequences.


Circulation ◽  
2004 ◽  
Vol 109 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Stephen J. White ◽  
Stuart A. Nicklin ◽  
Hildegard Büning ◽  
M. Julia Brosnan ◽  
Kristen Leike ◽  
...  

2017 ◽  
Vol 5 (24) ◽  
pp. 4732-4744 ◽  
Author(s):  
A. Venault ◽  
Y.-C. Huang ◽  
J. W. Lo ◽  
C.-J. Chou ◽  
A. Chinnathambi ◽  
...  

Although PEGylated polyplexes for gene delivery are widespread, there is a need for an in-depth investigation of the role of the PEGylation degree on the delivery efficiency of the systems.


2012 ◽  
Vol 36 (5) ◽  
pp. S62-S63
Author(s):  
Eva Tuduri ◽  
Maria M. Glavas ◽  
Robert K. Baker ◽  
Frank K. Huynh ◽  
Michael J. Riedel ◽  
...  

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