RNA interference:a potential novel therapeutic combating HIV-1 in the central nervous system

RNA interference (RNAi)is a conserved process by which eukaryotic cells protect their genomes utilizing small, double-stranded RNAs to degrade target RNAs. This occurs in a sequence-specific manner and is different from the interferon effect of larger double stranded RNAs. Post-transcriptional gene silencing by these nucleic acids can lead to degradation of either cellular or viral RNAs. It has been recently shown that double stranded, small interfering RNAs (siRNAs)of 21 to 25 nucleotides can be transfected into relevant cells to target specific RNAs. In addition, utilizing hairpin motifs, siRNAs can be expressed intracellularly using molecular therapeutic vectors. This potent approach has been utilized to both inhibit pathogens, including viruses, as well as to dissect cellular molecular mechanisms via a potent knockout effect. At this time in the HIV-1-pandemic,one of the remaining, most enigmatic, and still vitally important areas of HIV-1 pathogenesis occurs in the central nervous system (CNS).HIV-1-induced encephalopathy remains difficult to treat in the developing world and in parts of the developed world, even in the era of highly active anti-retroviral therapy. As such, novel approaches which could lead to intracellular immunization, and life-long resistance against HIV-1 encephalopathy would be of important impact worldwide. Thus, we now seek to combine our background in molecular therapeutics and RNAi with our long-standing interest in HIV-1 neuropathogenesis to target the CNS using siRNAs.