Swine acute diarrhea syndrome coronavirus induces autophagy to promote its replication via the Akt/mTOR pathway

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an enveloped, single-stranded, positive-sense RNA virus belonging to the Coronaviridae family. Increasingly studies have demonstrated that viruses could utilize Autophagy to promote their own replication. However, the relationship between SADS-CoV and Autophagy remains unknown. Here, we reported that SADS-CoV infection-induced Autophagy and pharmacologically increased Autophagy were conducive to viral proliferation. Conversely, suppression of Autophagy by pharmacological inhibitors or knockdown of autophagy-related protein impeded viral replication. Furthermore, we demonstrated the underlying mechanism by which SADS-CoV triggered Autophagy through the inactivation of the Akt/mTOR pathway. Importantly, we identified Integrin α3 (ITGA3) as a potential Antiviral target upstream of Akt/mTOR and Autophagy pathways. Knockdown of ITGA3 enhanced Autophagy and consequently increased the replication of SADS-CoV. Collectively, our studies revealed a novel mechanism that SADS-CoV-induced Autophagy to facilitate its proliferation via Akt/mTOR pathway and found that ITGA3 was an effective Antiviral factor for suppressing viral Infection.