Junín Virus Exploits Host's Cellular Autophagy Machinery

ARRÍAS PAULA NAZARENA; URE AGUSTÍN ENRIQUE; GÓMEZ RICARDO MARTIN; PEREZ VIDAKOVICS MARÍA LAURA; ROMANOWSKI VICTOR

Madison

Congreso; 36th Annual Meeting American Society for Virology; 2017

As an integral part of the immune system, autophagy participates in virusdetection and induction of antiviral defenses. Viruses have developedstrategies that directly or indirectly alter autophagy and promote variousstages of the viral cycle. Arenaviruses are enveloped viruses with twosegments of an ambisense single-stranded RNA genome. Some of theseviruses cause severe hemorrhagic fever in humans, including the NewWorld arenavirus Junin virus (JUNV). JUNV, classified as a category Apriority pathogen, is the causative agent of the Argentine hemorrhagic fever(AHF). There are currently no FDA-approved vaccines to prevent AHF.Recent studies suggest that arenaviruses can takeover host autophagicmachinery to promote viral replication and budding. In individuals withAHF, the severity and prognosis of the disease correlates with high levelsof IFN. The crosstalk between the IFN response and autophagic machinerywould impact viral replication. In the present study, we investigated the roleof autophagy in JUNV replication. We have observed that JUNV infectionsignificantly enhanced accumulation of LC3-positive punctate pattern (ahallmarks of cellular autophagosome formation) in human A549 cellstransfected with a RFP-LC3 plasmid. Protein samples from experimentsperformed in parallel and analyzed by Western blot showed an increaseof the LC3-II/LC3-I ratio in cells infected with JUNV after 24 h postinfection.We also found that inhibition of autophagy with BafilomicinA1, Chloroquine or 3-Methyladenine reduce virus replication. Conversely,induction of autophagy by treatment of A549 cells with rapamycin ornutrient deprivation resulted in increased JUNV replication. Finally, weobserved that siRNA targeting key autophagy genes (Atg5, Atg7, Beclin1)altered JUNV replication. Our results suggest that the host?s autophagymachinery is activated during JUNV infection to enhance the efficiencyof viral replication. Studying and understanding these mechanisms willenable the development of preventive and therapeutic strategies againstHFA and other arenaviral hemorrhagic fevers.