TY - JOUR
T1 - Enterovirus 71-induced autophagy increases viral replication and pathogenesis in a suckling mouse model
AU - Lee, Ying Ray
AU - Wang, Po Shun
AU - Wang, Jen Ren
AU - Liu, Hsiao Sheng
N1 - Funding Information:
We thank Dr. Robert Anderson and Peter Wilds for their critical reading of the manuscript. We also thank Dr. Jim-Tong Horng, Chang Gung University for providing the rat polyclonal anti-EV71 2C antibody. This work was supported by grants from the National Science Council, Taiwan (NSC-99-2745-B-006-002, NSC-101-2321-B-006-029-and 101-2320-B-006 -025 -MY3) and the Center of Infectious Disease and Signaling Research, NCKU, Tainan, Taiwan.
Funding Information:
We thank Dr. Robert Anderson and Peter Wilds for their critical reading of the manuscript. We also thank Dr. Jim-Tong Horng, Chang Gung University for providing the rat polyclonal anti-EV71 2C antibody. This work was supported by grants from the National Science Council, Taiwan (NSC-99-2745-B-006-002, NSC-101-2321-B-006-029- and 101-2320-B-006-025-MY3) and the Center of nfectious Disease and Signaling Research, NCKU, Tainan, Taiwan.
Publisher Copyright:
© 2014 Lee et al.
PY - 2014/8/20
Y1 - 2014/8/20
N2 - Background: We previously reported that Enterovirus 71 (EV71) infection activates autophagy, which promotes viral replication both in vitro and in vivo. In the present study we further investigated whether EV71 infection of neuronal SK-N-SH cells induces an autophagic flux. Furthermore, the effects of autophagy on EV71-related pathogenesis and viral load were evaluated after intracranial inoculation of mouse-adapted EV71 (MP4 strain) into 6-day-old ICR suckling mice. Results: We demonstrated that in EV71-infected SK-N-SH cells, EV71 structural protein VP1 and nonstructural protein 2C co-localized with LC3 and mannose-6-phosphate receptor (MPR, endosome marker) proteins by immunofluorescence staining, indicating amphisome formation. Together with amphisome formation, EV71 induced an autophagic flux, which could be blocked by NH4Cl (inhibitor of acidification) and vinblastine (inhibitor of fusion), as demonstrated by Western blotting. Suckling mice intracranially inoculated with EV71 showed EV71 VP1 protein expression (representing EV71 infection) in the cerebellum, medulla, and pons by immunohistochemical staining. Accompanied with these infected brain tissues, increased expression of LC3-II protein as well as formation of LC3 aggregates, autophagosomes and amphisomes were detected. Amphisome formation, which was confirmed by colocalization of EV71-VP1 protein or LC3 puncta and the endosome marker protein MPR. Thus, EV71-infected suckling mice (similar to EV71-infected SK-N-SH cells) also show an autophagic flux. The physiopathological parameters of EV71-MP4 infected mice, including body weight loss, disease symptoms, and mortality were increased compared to those of the uninfected mice. We further blocked EV71-induced autophagy with the inhibitor 3-methyladenine (3-MA), which attenuated the disease symptoms and decreased the viral load in the brain tissues of the infected mice. Conclusions: In this study, we reveal that EV71 infection of suckling mice induces an amphisome formation accompanied with the autophagic flux in the brain tissues. Autophagy induced by EV71 promotes viral replication and EV71-related pathogenesis.
AB - Background: We previously reported that Enterovirus 71 (EV71) infection activates autophagy, which promotes viral replication both in vitro and in vivo. In the present study we further investigated whether EV71 infection of neuronal SK-N-SH cells induces an autophagic flux. Furthermore, the effects of autophagy on EV71-related pathogenesis and viral load were evaluated after intracranial inoculation of mouse-adapted EV71 (MP4 strain) into 6-day-old ICR suckling mice. Results: We demonstrated that in EV71-infected SK-N-SH cells, EV71 structural protein VP1 and nonstructural protein 2C co-localized with LC3 and mannose-6-phosphate receptor (MPR, endosome marker) proteins by immunofluorescence staining, indicating amphisome formation. Together with amphisome formation, EV71 induced an autophagic flux, which could be blocked by NH4Cl (inhibitor of acidification) and vinblastine (inhibitor of fusion), as demonstrated by Western blotting. Suckling mice intracranially inoculated with EV71 showed EV71 VP1 protein expression (representing EV71 infection) in the cerebellum, medulla, and pons by immunohistochemical staining. Accompanied with these infected brain tissues, increased expression of LC3-II protein as well as formation of LC3 aggregates, autophagosomes and amphisomes were detected. Amphisome formation, which was confirmed by colocalization of EV71-VP1 protein or LC3 puncta and the endosome marker protein MPR. Thus, EV71-infected suckling mice (similar to EV71-infected SK-N-SH cells) also show an autophagic flux. The physiopathological parameters of EV71-MP4 infected mice, including body weight loss, disease symptoms, and mortality were increased compared to those of the uninfected mice. We further blocked EV71-induced autophagy with the inhibitor 3-methyladenine (3-MA), which attenuated the disease symptoms and decreased the viral load in the brain tissues of the infected mice. Conclusions: In this study, we reveal that EV71 infection of suckling mice induces an amphisome formation accompanied with the autophagic flux in the brain tissues. Autophagy induced by EV71 promotes viral replication and EV71-related pathogenesis.
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M3 - Article
C2 - 25139436
AN - SCOPUS:84925884548
SN - 1021-7770
VL - 21
JO - Journal of biomedical science
JF - Journal of biomedical science
IS - 1
M1 - 80
ER -
