Inhibition of HSV-1 replication by a gene editing strategy

HSV-1 is a human neurotropic virus and its genome is present in trigeminal ganglia of 85% of human population worldwide, with a seroprevalence of 90% in normal asymptomatic individuals. Replication of HSV-1 in the central nervous system causes encephalitis, resulting from the infection and anti-viral inflammatory response within the frontal and the temporal lobes. Current treatments for primary HSV-1 infection and reactivation of diseases are non-selective, do not prevent establishment of latent infection and have adverse side effects, pointing to a strong need for improved and specific therapeutic strategies. In this study, we used RNA-guided CRISPR/Cas9 gene editing to specifically target three of the viral immediate-early proteins, infected cell protein 0 (ICPO), lCP4, and lCP27, that are implicated in controlling further viral gene expression and affecting normal host cell function. We found that CRISPR/Cas9 introduced the excision of all the three target genes, completely abrogated HSV-1 infectivity in permissive human cell culture models and protected permissive cells against HSV-1 infection. We conclude that RNA-guided CRISPR/Cas9 can be used to develop a novel, specific and efficacious therapeutic and prophylactic platform for targeted viral genomic ablation to treat HSV-1 diseases.