Ultrasound targeted gene therapy in a mouse model of prostate cancer: Evaluation of immune response.

120Background: Gene transfer to malignant sites using human adenoviruses (hAd) has been limited because of their immunogenicity. Murine cells often lack some of the receptors needed for hAd infection; therefore, are generally non-permissive for hAd infection and replication, which limits translational studies of adenoviral gene transfer techniques. We developed a gene transfer method, which uses a combination of lipid-encapsulated perfluorocarbon microbubbles (MBs) and ultrasound (US) to shield and deliver hAds to a specific tissue bypassing the requirement of the coxsackie and adenovirus receptor (CAR). Methods: Transduction efficiency and GFP protein expression of hAd.GFP was assessed by flow cytometry and fluorescence microscopy in murine TRAMP-C2 and human DU145 prostate cancer cells. Innate and acquired immunity response was determined by ELISA and CTL assay in C57BL/6 mice bearing TRAMP-C2 syngeneic tumor grafts following injections of MBs-Ad.GFP complexes in the presence or absence of ultrasound. R...