Hepatitis C virus (HCV) is an important human pathogen that can cause severe liver diseases including acute and chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Studies in recent years indicated that HCV could induce autophagy both in vitro and in vivo to enhance its replication. As autophagy plays an important role in maintaining cellular homeostasis, the prolonged perturbation of this pathway by HCV during chronic infection can have profound consequences on the progression of liver diseases in HCV- infected patients. Although significant progresses have been made during the past few years to understand the relationship between HCV and autophagy, many questions remain unanswered. The goal of this research is to continue our previous studies to further understand the relationship between HCV and autophagy.
In Aim 1, we will continue our previous studies to investigate the biogenesis pathway of autophagosomes in HCV-infected cells by identifying the origin of these membrane vesicles and determine whether they are derived from the homotypic fusion of phagophores. As our recent studies indicated that HCV induced autophagy via a non-canonical pathway, in Aim 2, we will continue to delineate this pathway and examine the roles of HCV nonstructural proteins in the induction of this pathway. In addition, as our preliminary studies revealed the specific association of lipid rafts with autophagosomes induced by HCV, we will also investigate how lipid rafts are recruited to HCV-induced autophagosomes and their possible role in mediating HCV RNA replication on autophagosomal membranes. We have recently developed a novel approach to purify autophagosomes from HCV-infected cells for the identification of their associated protein factors.
In Aim 3, we will continue to characterize these protein factors, which include annexin A2, apolipoprotein E and syntaxin 7, and determine their possible roles in the biogenesis of autophagosomes and HCV replication. Our proposed research will provide important information for understanding the interaction between HCV and its host cells and lead to a better understanding of the HCV life cycle and its pathogenesis. It will also provide important information for understanding the cellular autophagic pathway, which is frequently exploited by viruses to enhance their replication.

Public Health Relevance

Hepatitis C virus (HCV) is an important human pathogen that can cause severe liver diseases. The proposed research to study the interaction between HCV and its host cells will generate important information for understanding the replication and pathogenesis of HCV and lead to better care for HCV patients with severe liver diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK094652-09
Application #
9891047
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Doo, Edward
Project Start
2011-09-21
Project End
2021-03-31
Budget Start
2020-04-01
Budget End
2021-03-31
Support Year
9
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Southern California
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Wang, Linya; Ou, Jing-Hsiung James (2018) Regulation of Autophagy by Hepatitis C Virus for Its Replication. DNA Cell Biol 37:287-290
Kim, Ja Yeon; Ou, Jing-Hsiung James (2018) Regulation of Apolipoprotein E Trafficking by Hepatitis C Virus-induced Autophagy. J Virol :
Wang, Linya; Kim, Ja Yeon; Liu, Helene Minyi et al. (2017) HCV-induced autophagosomes are generated via homotypic fusion of phagophores that mediate HCV RNA replication. PLoS Pathog 13:e1006609
Kim, Ja Yeon; Wang, Linya; Lee, Jiyoung et al. (2017) Hepatitis C Virus Induces the Localization of Lipid Rafts to Autophagosomes for Its RNA Replication. J Virol 91:
Liu, Kai; Lee, Jiyoung; Kim, Ja Yeon et al. (2017) Mitophagy Controls the Activities of Tumor Suppressor p53 to Regulate Hepatic Cancer Stem Cells. Mol Cell 68:281-292.e5
Chan, Stephanie T; Ou, Jing-Hsiung James (2017) Hepatitis C Virus-Induced Autophagy and Host Innate Immune Response. Viruses 9:
Klionsky, Daniel J (see original citation for additional authors) (2016) Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). Autophagy 12:1-222
Chan, Stephanie T; Lee, Jiyoung; Narula, Mansi et al. (2016) Suppression of Host Innate Immune Response by Hepatitis C Virus via Induction of Autophagic Degradation of TRAF6. J Virol 90:10928-10935
Wang, Linya; Tian, Yongjun; Ou, Jing-hsiung James (2015) HCV induces the expression of Rubicon and UVRAG to temporally regulate the maturation of autophagosomes and viral replication. PLoS Pathog 11:e1004764
Luo, Guangxiang George; Ou, Jing-hsiung James (2015) Oncogenic viruses and cancer. Virol Sin 30:83-4

Showing the most recent 10 out of 20 publications