The discovery of novel adeno-associated viruses (AAV) and their development as vectors has been an important accomplishment of this project in the first two cycles of this program project. While we are encouraged by the improved performance profiles of the novel AAV based vectors there is much to be learned before they can be responsibly evaluated in humans. This project will identify the AAV capsid that confers the most attractive performance profile as a vector following liver directed gene transfer. Key issues of vector immunology which may impact on safety and efficacy will be thoroughly characterized.
Specific Aim #1 will evaluate the potential of two possible AAV clinical candidates for potential applications in humans. The first set of studies will measure gene transfer efficiency into human hepatocytes grown as xenografts in immune deficient mice. The AAV Clinical Candidate also will be evaluated in murine models of familial hypercholesterolemia (FH) and abetalipoproteinemia (ABL) for gene transfer efficiency, toxicity and vector immunogenicity. The second and third specific aims will evaluate an hypothesis that emerged from a phase I clinical trial with AAV serotype 2 in subjects with hemophilia B. These investigators proposed that the input capsid proteins of the vector activated cytotoxic T lymphoctyes (CTLs) that target and kill transduced hepatocytes leading to loss of transgene expression and self-limited hepatitis. This grant will evaluate in mice and monkeys the potential of the Clinical Candidate to active T cells and the role of memory T cells to the capsid in this activation step. Experiments will also be directed to the second key aspect of this hypothesis which is the cross presentation of input capsid by the hepatocytes to render them targets for CTLs. In an attempt to study this key step in the most relevant biological setting, experiments will be performed in xenograft mice that are reconstituted with human CTLs specific to an epitope on the capsid;the mice will be engineered to express a human HLA in hepatocytes. A fully "humanized" model will be developed in which animals are reconstituted with both human liver and human T cells to study cross presentation of capsid and T cell targeting.

Public Health Relevance

Lay abstract. This project will develop a viral vector with optimal properties for directing genes to liver. Studies will also be performed to determine what the risk would be of immune rejection of the vector and vector corrected cells.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Program Projects (P01)
Project #
Application #
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Pennsylvania
United States
Zip Code
Liu, Lijun; Nam, Minwoo; Fan, Wei et al. (2014) Nutrient sensing by the mitochondrial transcription machinery dictates oxidative phosphorylation. J Clin Invest 124:768-84
Mikals, Kyle; Nam, Hyun-Joo; Van Vliet, Kim et al. (2014) The structure of AAVrh32.33, a novel gene delivery vector. J Struct Biol 186:308-17
Wang, Dan; Zhong, Li; Nahid, M Abu et al. (2014) The potential of adeno-associated viral vectors for gene delivery to muscle tissue. Expert Opin Drug Deliv 11:345-64
Wang, Dan; Gao, Guangping (2014) State-of-the-art human gene therapy: part I. Gene delivery technologies. Discov Med 18:67-77
Wang, Dan; Gao, Guangping (2014) State-of-the-art human gene therapy: part II. Gene therapy strategies and clinical applications. Discov Med 18:151-61
Lock, Martin; Alvira, Mauricio R; Chen, Shu-Jen et al. (2014) Absolute determination of single-stranded and self-complementary adeno-associated viral vector genome titers by droplet digital PCR. Hum Gene Ther Methods 25:115-25
Gao, Kai; Li, Mengxin; Zhong, Li et al. (2014) Empty Virions In AAV8 Vector Preparations Reduce Transduction Efficiency And May Cause Total Viral Particle Dose-Limiting Side-Effects. Mol Ther Methods Clin Dev 1:20139
Somanathan, Suryanarayan; Jacobs, Frank; Wang, Qiang et al. (2014) AAV vectors expressing LDLR gain-of-function variants demonstrate increased efficacy in mouse models of familial hypercholesterolemia. Circ Res 115:591-9
Kassim, Sadik H; Li, Hui; Bell, Peter et al. (2013) Adeno-associated virus serotype 8 gene therapy leads to significant lowering of plasma cholesterol levels in humanized mouse models of homozygous and heterozygous familial hypercholesterolemia. Hum Gene Ther 24:19-26
Gruntman, Alisha M; Bish, Lawrence T; Mueller, Christian et al. (2013) Gene transfer in skeletal and cardiac muscle using recombinant adeno-associated virus. Curr Protoc Microbiol Chapter 14:Unit 14D.3

Showing the most recent 10 out of 126 publications