RNA interference (RNAi) is a powerful tool to silence gene expression post-transcriptionally. Delivering sequences of RNAi in vivo remains a problem. The aim of this study was to use JC virus (JCV) virus-like particles (VLPs) as a vector for delivering RNAi in silencing the cytokine gene of IL-10. Methods: JCV VLPs were generated by recombinant JCV VP1 protein in yeast expression system. DNA fragment containing IL-10 shRNA was packaged into VLPs by osmotic shock. Results: In RAW cells, IL-10 shRNA was found to reduce IL-10 expression by 85 to 89%, as compared with VLPs alone. IL-10 shRNA did not. | Chou et al. Journal of Biomedical Science 2010 17 51 http content 17 1 51 a NSC Tha cost of publication In Journal of Blomodlcal Science Is bome by tlM National Science Council Taiwan JOURNAL OF BIOMEDICAL SCIENCE RESEARCH Open Access In vitro and in vivo targeted delivery of IL-10 interfering RNA by JC virus-like particles Meng-Ing Chou41 Yu-Fan Hsiehf2 Meilin Wang3 Jinghua Tsai Chang4 Deching Chang5 Moncef Zouali6 7 and Gregory J Tsay 1 2 8 Abstract Background RNA interference RNAi is a powerful tool to silence gene expression post-transcriptionally. Delivering sequences of RNAi in vivo remains a problem. The aim of this study was to use JC virus JCV virus-like particles VLPs as a vector for delivering RNAi in silencing the cytokine gene of IL-10. Methods JCV VLPs were generated by recombinant JCV VP1 protein in yeast expression system. DNA fragment containing IL-10 shRNA was packaged into VLPs by osmotic shock. Results In RAW cells IL-10 shRNA was found to reduce IL-10 expression by 85 to 89 as compared with VLPs alone. IL-10 shRNA did not cross-react with TNF-alpha mRNA or influence the expression of TNF-alpha. In BALB c mice IL-10 shRNA could reduce 95 of IL-10 secretion. Surprisingly it also down regulated TNF-alpha expression. Conclusions We show for the first time that JCV VLPs empty capsids are competent vectors to deliver RNAi and are nontoxic to cells suggesting that JCV VLPs is an efficient agent to deliver RNAi in both murine macrophage cells and BALB c mice. This system provides an efficient means for delivering the RNAi for gene therapy purposes. Background Transfection of RNA interference RNAi into living cells is a major technique in studying the biological function of genes and for their potential treatment of human diseases. There are considerable excitements about its potential therapeutic applications in human diseases 13 . RNAi offers the prospects of higher specificity lower immunogenicity and greater disease .
