186. Secreted Extracellular Vesicles of Baculovirus GP64 Interact with Plasmid DNA to Enhance Transfection

Top of pageAbstract We are pursuing methods for the in vitro production of complexes of DNA with viral envelope proteins to assemble nanoparticles with gene transferring properties. Toward that end, we have previously shown that assembled vesicles consisting largely of the glycoprotein of the vesicular Stomatitis virus (VSV-G) are produced and efficiently released into the conditioned medium from cells expressing VSV-G in absence of other viral components. We have also shown that VSV-G vesicles partially purified from such conditioned medium interact with plasmid DNA to produce complexes with enhanced transfection capability. We report here that the alternative efficient retrovirus pseudotyping envelope protein, the GP64 of baculovirus Autographa californica nucleopolyhedrovirus, is also found in conditioned medium or GP64-transfected cells and that pelleted, partially purified GP64 can interact in vitro with plasmid DNA to enhance plasmid transfection efficiency in the presence of Polybrene to a degree similar to that of VSV-G. We have also examined plasmid transfection efficiency mediated by VSV-G/plasmid and GP64/plasmid complexes in the presence of either Polybrene or the transduction domain of HIV-1 Tat, one of a variety of small cell-penetrating peptides that have been shown to promote cell uptake of DNA and other hydrophilic molecules and also to increase virus vector-mediated gene transfer. In the presence of partially purified vesicles of either VSV-G or GP-64, Polybrene produced a much greater degree of enhanced transfection than did HIV-1 Tat protein.