Ilaprazole and other novel prazole-based compounds that bind Tsg101 inhibit viral budding of HSV-1/2 and HIV from cells

Abstract In many enveloped virus families, including HIV and HSV, a crucial, yet unexploited, step in the viral life cycle is releasing particles from the infected cell membranes. This release process is mediated by host ESCRT complex proteins, which is recruited by viral structural proteins and provides the mechanical means for membrane scission and subsequent viral budding. The prazole drug, tenatoprazole, was previously shown to bind to ESCRT complex member Tsg101 and quantitatively block the release of infectious HIV-1 from cells in culture. In this report we show that tenatoprazole and a related prazole drug, ilaprazole, effectively block infectious Herpes Simplex Virus (HSV)-1/2 release from Vero cells in culture. By electron microscopy, we found that both prazole drugs block the release of HSV particles from the cell nuclear membrane resulting in their accumulation in the nucleus. Ilaprazole also quantitatively blocks the release of HIV-1 from 293T cells with an EC 50 of 0.8 μM, which is more potent than tenatoprazole. Finally, we synthesized and tested multiple novel prazole-based analogs that demonstrate both binding to Tsg101 and inhibition of viral egress in the nanomolar range of HIV-1 from 293T cells. Our results indicate that prazole-based compounds may represent a class of drugs with potential to be broad-spectrum antiviral agents against multiple enveloped viruses, by interrupting cellular Tsg101 interaction with maturing virus, thus blocking the budding process that releases particles from the cell. Importance These results provide the basis for the development of drugs that target enveloped virus budding that can be used ultimately to control multiple virus infections in humans.