Retinoic Acid Analogs Inhibit Human Herpesvirus 8 Replication

In the present study, we show that retinoids inhibit Human Herpesvirus 8 (HHV-8) replication, and identify new retinoid compounds with a strong antiviral effect. The compounds specifically inhibited viral promoters, both during the early and the late phases of infection in all the cell systems tested, and resulted in up to 100-fold reduction of viral titer and release of progeny virus. The inhibition of viral replication induced by retinoids in endothelial cells, primary target of HHV-8 driven transformation in Kaposi's Sarcoma, prevented endothelial cells from developing spindle morphology and in vitro tube formation, characteristic changes associated with HHV-8 infection and transformation. Selective retinoids, particularly those with RAR agonist activity, may be good candidates for the development of antiviral drugs that may also