The early autophagic pathway is activated by hepatitis B virus and required for viral DNA replication.
Autophagy is a catabolic process by which cells remove long-lived proteins and damaged organelles for recycling. Viral infections may also induce autophagic response. Here we show that hepatitis B virus (HBV), a pathogen that chronically infects approximately 350 million people globally, can enhance autophagic response in cell cultures, mouse liver, and during natural infection. This enhancement of the autophagic response is not coupled by an increase of autophagic protein degradation and is dependent on the viral X protein, which binds to and enhances the enzymatic activity of phosphatidylinositol 3-kinase class III, an enzyme critical for the initiation of autophagy. Further analysis indicates that autophagy enhances HBV DNA replication, with minimal involvement of late autophagic vacuoles in this process. Our studies thus demonstrate that a DNA virus can use autophagy to enhance its own replication and indicate the possibility of targeting the autophagic pathway for the treatment of HBV patients.
Sir
Donna
D
Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA.
Tian
Yongjun
Y
Chen
Wen-ling
WL
Ann
David K
DK
Yen
Tien-Sze Benedict
TS
Ou
Jing-Hsiung James
JH
D000818:Animals; D001343:Autophagy; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002478:Cells, Cultured; D004279:DNA, Viral / Q000096:biosynthesis*; D004789:Enzyme Activation; D006515:Hepatitis B virus / Q000235:genetics / Q000502:physiology*; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D034741:RNA, Small Interfering; D014779:Virus Replication
D004279:DNA, Viral; D034741:RNA, Small Interfering; D019869:Phosphatidylinositol 3-Kinases