RNA Interference Prevents Genital Herpes in Mice

Small interfering RNA molecules (siRNAs) can selectively silence expression of genes. Previously, we reported that this technique could stifle genital herpes infections if the siRNAs were applied just before herpes challenge (JW Jan 20 2006). However, for practical purposes, a vaginal microbicide would have to inhibit infection for a longer time.

A team from Harvard Medical School created a vaginal microbicide that contained siRNAs that silenced key genes within herpes simplex virus type 2 (HSV-2) and a gene for an epithelial cell receptor to which HSV-2 attaches. The siRNAs were chemically protected against destruction by RNases and were conjugated to cholesterol to encourage cellular uptake. Following vaginal challenge with a high concentr…