JC polyomavirus (JCPyV) is a ubiquitous,
double-stranded DNA virus that causes the fatal
demyelinating disease progressive multifocal leukoencephalopathy (PML) in immunocompromised patients. Current treatments for PML are limited to immune reconstitution, and no effective
antivirals exist. In this report, we show that the
oxindole GW-5074 (3-(3,5-dibromo-4-hydroxybenzylidene)-5-iodoindolin-2-one) reduces JCPyV
infection in primary and immortalized cells. This compound potently inhibits virus spread, which suggests that it could control infection in PML patients. We demonstrate that
GW-5074 inhibits endogenous ERK phosphorylation, and that JCPyV
infection in GW-5074-treated cells cannot be rescued with ERK agonists, which indicates that the
antiviral mechanism may involve its antagonistic effects on MAPK-ERK signaling. Importantly,
GW-5074 exceeds thresholds of common pharmacological parameters that identify promising compounds for further development. This MAPK-ERK antagonist warrants further investigation as a potential treatment for PML. IMPORTANCE Human polyomaviruses, such as JCPyV and BKPyV, cause significant morbidity and mortality in immunocompromised or immunomodulated patients. There are no treatments for polyomavirus-induced diseases other than restoration of immune function. We discovered that the
oxindole GW-5074 potently inhibits
infection by both JCPyV and BKPyV. Further optimization of this compound could result in the development of
antiviral therapies for polyomavirus-induced diseases.