Transkingdom RNA interference (tkRNAi): a novel method to induce therapeutic gene silencing.

RNA interference is a phenomenon in which specific, endogenous genes are silenced by mRNA degradation. This technology is highly regarded as a potential therapeutic due to its high efficacy and low toxicity. However, the difficulty of delivering RNAi to target cells has impeded the development of RNAi-based therapies. One method to overcome this barrier is the use of a nonpathogenic bacteria vector, Escherichia coli, to deliver RNAi to target cells with high efficacy. In transkingdom interference RNAi (tkRNAi) delivery, E. coli were engineered to transcribe short RNA (shRNA) from a plasmid (TRIP) containing the invasin gene Inv and the listeriolysin O gene Hly. tkRNAi is successful in eliciting efficient gene silencing in vitro and in vivo.