We are engineering two adenovirus capsid proteins, the fiber and penton, to deliver genes in a targeted, ligand-directed fashion in the absence of both a viral genome and expression of other adenoviral proteins. The adenovirus capsid fiber, which normally binds ubiquitously expressed viral receptors, is being engineered by incorporation of a targeting ligand, heregulin, which binds specifically to certain breast cancer cells. Our DNA constructs encode two types of recombinant fibers. In Fiber A, the receptor binding domain of heregulin replaces a portion of the wild-type fiber knob, allowing fiber trimerization to remain intact. In Fiber B, heregulin sequences replace the C-terminal portion of a "knobless" fiber, resulting in fiber monomers only. The adenovirus penton, which mediates cellular internalization and escape from the endosomat compartment, is engineered to carry exogenous DNA by addition of a polylysine sequence. These recombinant proteins are being tested for their ability to assemble into functional fiber-penton complexes that (:an target gene delivery to specific cells. Our preliminary data shows that recombinant pentons expressed from bacteria can pentamerize, bind DNA. and deliver a reporter plasmid to (:ells in culture. We are currently expressing our recombinant protein in a bacuh)virus expression system to obtain preparative amounts of protein for further testing of our system.
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology