Discovery of a novel class of broad-spectrum antivirals targeting the UEV domain of TSG101 in the host ESCRT pathway.

The persistent threat of emerging and re-emerging viral outbreaks underscores an urgent need for broad-spectrum antivirals (BSAs). A promising strategy involves targeting host factors exploited by different viral families to develop new BSAs with a high barrier to resistance development. The present work focuses on the inhibition of the protein-protein interactions (PPIs) between viral late domains (L-domain) and the TSG101 protein from the host ESCRT pathway, which is exploited by multiple highly pathogenic viruses for their replication and budding, hence representing a crucial yet underexplored therapeutic strategy to inhibit viral replication. Starting from the previously identified hit compound UEV-10, we developed a series of simplified, more druggable quinoline analogues. These derivatives effectively inhibited the TSG101/L-domain interaction at low micromolar concentrations and were active in a series of cell-based assays, including high-content bimolecular complementation, virus-like particle release, and viral growth inhibition of several biosafety level 4 (BSL-4) pathogens (Ebola, Marburg, and Nipah viruses) and non-enveloped enteroviruses (EV-D68). Overall, our findings further support the inhibition of TSG101/L-domain PPIs as an effective and versatile strategy for the development of broad-spectrum antiviral agents with potential applicability across diverse viral families.