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.
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.
|Ai, Jianzhong; Tai, Phillip W L; Lu, Yi et al. (2017) Characterization of adenoviral transduction profile in prostate cancer cells and normal prostate tissue. Prostate 77:1265-1270|
|Ai, Jianzhong; Li, Jia; Gessler, Dominic J et al. (2017) Adeno-associated virus serotype rh.10 displays strong muscle tropism following intraperitoneal delivery. Sci Rep 7:40336|
|Calcedo, Roberto; Somanathan, Suryanarayan; Qin, Qiuyue et al. (2017) Class I-restricted T-cell responses to a polymorphic peptide in a gene therapy clinical trial for ?-1-antitrypsin deficiency. Proc Natl Acad Sci U S A 114:1655-1659|
|Ajufo, Ezim; Cuchel, Marina (2016) Recent Developments in Gene Therapy for Homozygous Familial Hypercholesterolemia. Curr Atheroscler Rep 18:22|
|Ibrahim, Salam; Somanathan, Suryanarayan; Billheimer, Jeffrey et al. (2016) Stable liver-specific expression of human IDOL in humanized mice raises plasma cholesterol. Cardiovasc Res 110:23-9|
|Calcedo, Roberto; Wilson, James M (2016) AAV Natural Infection Induces Broad Cross-Neutralizing Antibody Responses to Multiple AAV Serotypes in Chimpanzees. Hum Gene Ther Clin Dev 27:79-82|
|Rashnonejad, Afrooz; Chermahini, Gholamhossein Amini; Li, Shaoyong et al. (2016) Large-Scale Production of Adeno-Associated Viral Vector Serotype-9 Carrying the Human Survival Motor Neuron Gene. Mol Biotechnol 58:30-6|
|Xie, Jun; Burt, Daniel Robert; Gao, Guangping (2015) Adeno-associated virus-mediated microRNA delivery and therapeutics. Semin Liver Dis 35:81-8|
|Ahmed, Seemin S; Gao, Guangping (2015) Making the White Matter Matters: Progress in Understanding Canavan's Disease and Therapeutic Interventions Through Eight Decades. JIMD Rep 19:11-22|
|Wang, Lili; Bell, Peter; Somanathan, Suryanarayan et al. (2015) Comparative Study of Liver Gene Transfer With AAV Vectors Based on Natural and Engineered AAV Capsids. Mol Ther 23:1877-87|
Showing the most recent 10 out of 144 publications