Sustained ex vivo and in vivo transfer of a reporter gene using polyoma virus pseudocapsids

Properties of a virus-like artificial gene delivery vehicle, synthesised fr om recombinant major coat protein of mouse polyoma virus. have been explore d. The protein, VPI, self assembles into protein spheres, or 'pseudocapsids : which can bind and transfer DNA into cells in vitro and in vivo. Here, th e ability of pseudocapsids to carry DNA into a complex cell system lex vivo organ cultures of rabbit corneal or whole animals (mice) has been assessed . Evidence from histochemical and PCR experiments indicate that pseudocapsi ds stimulate uptake and stable maintenance of marker DNA in nondividing cor neal cells as efficiently as a recombinant adenovirus. in athymic and immun ocompetent mice, gene transmission occurs with no apparent adverse effects on the animals. In the presence of pseudocapsids, the marker gene was trans ferred to a range of organs, including the brains of animals, following per ipheral or intranasal administration. in immunocompetent mice, significant longterm transcriptional expression (at least 22 weeks) was observed with p seudocapsids, a period significantly longer than observed with DNA alone (s everal weeks only), again with no obvious adverse effects. This study demon strates that pseudocapsids from the murine virus, polyoma, constitute a nov el transfer agent for long-term gene therapeutic applications in tissues or whole animals.