Advisory Committee Chair
David T Curiel
Advisory Committee Members
Hongju Wu
Paul D Gamlin
Kent T Keyser
Theresa V Strong
Shu-Zhen Wang
Document Type
Dissertation
Date of Award
2009
Degree Name by School
Doctor of Philosophy (PhD) School of Optometry
Abstract
Adenovirus (Ad) is the most commonly used viral vector in gene therapy applications to date for a broad range of diseases. Although Ad-based viral vectors have many advantages in a variety of gene therapy designs, the commonly used adenoviral vectors have several key shortcomings. Those shortcomings include (1) inefficient transduction in cell types devoid of Ad’s native receptors and the incapability of gene delivery to targets behind physical barriers; (2) restricted accessibility to the central nerve system due to the existence of the blood-brain barrier (BBB); (3) lack of a useful strategy and platform to generate multi-functionality displaying Ad vectors as to achieve functional integration or synergism, which could improve Ad’s utility. We hypothesized that 1) incorporation of targeting ligands onto fiber protein would broaden the delivery range of Ad vectors in terms of cell types; 2) retargeting adenoviral vectors to the native transcytosis pathway in BBB endothelial cells would allow efficient gene delivery into the brain; 3) incorporation of multiple heterologous peptide ligands into a single Ad virion at the minor capsid protein IX (pIX) locales could allow for the display of multiple functionalities simultaneously, thus giving rise to functional integration or synergistic effect. To achieve the modification of Ad fiber and consequent expansion of gene delivery targets, the protein transduction domain of HIV-1 Tat protein (PTDtat) or melanotransferrin protein (MTf) was incorporated into the fiber knob protein via a genetic or non-genetic approach, respectively. The derived Ad vector incorporated with PTDtat showed expanded tropism and enhanced transduction efficiency in various tumor cells; the derived Ad vector incorporated with MTf achieved gene delivery across the BBB in an in vitro model. To incorporate three heterologous peptide ligands into a single Ad virion at the pIX locale, three modified pIX genes were genetically engineered and inserted into the Ad genome, resulting in the expression and incorporation of three different types of IX-ligand fusion proteins. The results indicated that capsid modification is a potent and useful strategy to enhance the efficacy of Ad vectors in gene therapy applications. However, this study mainly focused on the principle of capsid-modifying strategies, and further optimizations are necessary for their application for clinical trials.
Recommended Citation
Tang, Yizhe, "Modification of Adenovirus Capsid Proteins for Gene Therapy Applications" (2009). All ETDs from UAB. 108.
https://digitalcommons.library.uab.edu/etd-collection/108