Quercetin Regulates Autophagy to Inhibit PRRSV Replication Through the PI3K/Akt/mTOR Signaling Pathway

Porcine Reproductive and Respiratory Syndrome (PRRS), caused by the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), is a highly contagious viral disease responsible for significant economic losses in the global swine industry. Quercetin, a polyphenolic flavonoid known for its antiviral properties, was investigated in this study for its ability to inhibit PRRSV replication by modulating autophagy. Our study demonstrates that quercetin can inhibit PRRSV replication in MARC-45 cells by regulating the degradation of autophagosomes and suppressing the generation of autophagosome. We further suggest that quercetin inhibits PRRSV-induced autophagy via the PI3K/Akt/mTOR signaling pathway, suppressing autophagosome formation while promoting autophagosome-lysosome fusion, ultimately leading to reduced PRRSV replication. In conclusion, our study demonstrates that quercetin inhibits PRRSV replication by regulating autophagy through the PI3K/Akt/mTOR pathway.