The protective role of the HSP90 inhibitor, STA-9090, in lungs of SARS-CoV-2-infected Syrian golden hamsters
The emergence of new SARS-CoV-2 variants, capable of escaping the humoral immunity acquired by the available vaccines, together with waning immunity and vaccine hesitancy, challenges the efficacy of the vaccination strategy in fighting COVID-19. Improved therapeutic strategies are urgently needed to better intervene particularly in severe cases of the disease. They should aim at controlling the hyper-inflammatory state generated upon infection, reducing lung tissue pathology, and inhibiting viral replication. Previous research has pointed to a possible role for the chaperone HSP90 in SARS-CoV-2 replication and COVID-19 pathogenesis. Pharmacological intervention through HSP90 inhibitors was shown to be beneficial in the treatment of inflammatory diseases, infections and reducing replication of diverse viruses. In this study, we investigated the effects of the potent HSP90 inhibitor Ganetespib in vitro on alveolar epithelial cells and alveolar macrophages to characterize its effects on cell activation and viral replication. Additionally, the Syrian hamster animal model was used to evaluate its efficacy in controlling systemic inflammation and viral burden after infection in vivo. In vitro, Ganetespib reduced viral replication on alveolar epithelial cells in a dose-dependent manner and lowered significantly the expression of pro-inflammatory genes, in both alveolar epithelial cells and alveolar macrophages. In vivo, although no reduction in viral load was observed, administration of Ganetespib led to an overall improvement of the clinical condition of infected animals, with decreased systemic inflammation, reduced edema formation and lung tissue pathology. Altogether, we show that Ganetespib could be a potential treatment option for moderate and severe cases of COVID-19. Overall design: Total RNA sequencing was performed on AECs, alveolar macrophages and blood from hamsters, infected with SARS-CoV-2, to evaluate the effects of the HSP90 inhibitor Ganetespib on cell activation and viral replication. Differentially expressed genes analysis was performed, aiming at genes related to cell activation and inflammation.