title: Induction of Atypical Autophagy by Porcine Hemagglutinating Encephalomyelitis Virus Contributes to Viral Replication.
abstract: Autophagy is a basic biological metabolic process involving in intracellular membrane transport pathways that recycle cellular components and eliminate intracellular microorganisms within the lysosome. Autophagy also plays an important part in virus infection and propagation. However, some pathogens, including viruses, have evolved unique trick to escape or exploit autophagy. This study explores the mechanism of autophagy induction by porcine hemagglutinating encephalomyelitis virus (PHEV) in Neuro-2a cells, and examines the role of autophagy in PHEV replication. PHEV triggered autophagy in Neuro-2a cells is dependent on the presence of bulk double- or single-membrane vacuoles, the accumulation of GFP-LC3 fluorescent dots, and the LC3 lipidation. In addition, PHEV induced an incomplete autophagic effect because the degradation level of p62 did not change in PHEV-infected cells. Further validation was captured using LysoTracker and lysosome-associated membrane protein by indirect immunofluorescence labeling in PHEV-infected cells. We also investigated the change in viral replication by pharmacological experiments with the autophagy inducer rapamycin or the autophagy inhibitor 3-MA, and the lysosomal inhibitor chloroquine (CQ). Suppression of autophagy by 3-MA increased viral replication, compared with the mock treatment, while promoting of autophagy by rapamycin reduced PHEV replication. CQ treatment enhanced the LC3 lipidation in PHEV-infected Neuro-2a cells but lowered PHEV replication. These results show that PHEV infection induces atypical autophagy and causes the appearance of autophagosomes but blocks the fusion with lysosomes, which is necessary for the replication of PHEV in nerve cells.
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Yungang
authors.initials: Y
authors.lastname: Lan
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Zi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Lv
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Su
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University Changchun, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Lu
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China.
authors.forename: Wenqi
authors.initials: W
authors.lastname: He
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000071182:Autophagosomes / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology*; D001343:Autophagy / Q000187:drug effects / Q000502:physiology*; D000073641:Betacoronavirus 1 / Q000472:pathogenicity / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival; D002738:Chloroquine / Q000494:pharmacology; D018352:Coronavirus Infections / Q000821:virology; D008247:Lysosomes / Q000378:metabolism / Q000821:virology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D020123:Sirolimus / Q000494:pharmacology; D014617:Vacuoles / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects / Q000502:physiology*
chemical_list: D008565:Membrane Proteins; C025946:3-methyladenine; D002738:Chloroquine; D000225:Adenine; D020123:Sirolimus
keywords: LC3; atypical autophagy; autophagic flux; neuro-2a cells; neurotropic virus; porcine hemagglutinating encephalomyelitis virus; virus replication