E2 of Hepatitis C Virus Inhibits Apoptosis1

Hepatitis C virus (HCV) is the major causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, and can be involved in very long chronic infections up to 30 years or more. Therefore, it has been speculated that HCV possesses mechanisms capable of modulating host defense systems such as innate and adaptive immunity. To investigate this virus-host interaction, we generated HCV replicons containing various HCV structural proteins and then analyzed the sensitivity of replicon-containing cells to the apoptosis-inducing agent, TRAIL. TRAIL-induced apoptosis was monitored by cleavage of procaspase-3 and procaspase-9 as well as that of their substrate poly(ADP-ribose) polymerase. TRAIL-induced apoptosis was inhibited in cells expressing HCV E2. Moreover, expression of HCV E2 enhanced the colony forming efficiency of replicon-containing cells by 25-fold. Blockage of apoptosis by E2 seems to be related to inhibition of TRAIL-induced cytochrome c release from the mitochondria. Based on these results, we propose that E2 augments persistent HCV infection by blocking host-induced apoptosis of infected cells.

[1]  P. Thompson,et al.  The NS3 protein of hepatitis C virus induces caspase-8-mediated apoptosis independent of its protease or helicase activities. , 2004, Virology.

[2]  M. Kohara,et al.  Hepatitis C virus core protein binds to apolipoprotein AII and its secretion is modulated by fibrates , 1999, Hepatology.

[3]  K. Kirkegaard,et al.  Nonstructural Protein Precursor NS4A/B from Hepatitis C Virus Alters Function and Ultrastructure of Host Secretory Apparatus , 2003, Journal of Virology.

[4]  G. Barber.  Host defense, viruses and apoptosis , 2001, Cell Death and Differentiation.

[5]  C. Benedict,et al.  Death and survival: viral regulation of TNF signaling pathways. , 2003, Current opinion in immunology.

[6]  G. McFadden,et al.  Apoptosis: an innate immune response to virus infection. , 1999, Trends in microbiology.

[7]  V. Dixit,et al.  Apoptosis control by death and decoy receptors. , 1999, Current opinion in cell biology.

[8]  P. Branton,et al.  Regulation of apoptosis by viral gene products , 1997, Journal of virology.

[9]  J. Bertin,et al.  Death effector domain-containing herpesvirus and poxvirus proteins inhibit both Fas- and TNFR1-induced apoptosis. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[10]  J. Park,et al.  Hepatitis C virus nonstructural protein NS4B transforms NIH3T3 cells in cooperation with the Ha-ras oncogene. , 2000, Biochemical and biophysical research communications.

[11]  R. Bartenschlager,et al.  Enhancement of Hepatitis C Virus RNA Replication by Cell Culture-Adaptive Mutations , 2001, Journal of Virology.

[12]  B. McManus,et al.  Bcl-2 and Bcl-xL overexpression inhibits cytochrome c release, activation of multiple caspases, and virus release following coxsackievirus B3 infection. , 2003, Virology.

[13]  Yoon Ki Kim,et al.  Domains I and II in the 5' nontranslated region of the HCV genome are required for RNA replication. , 2002, Biochemical and biophysical research communications.

[14]  D. Green,et al.  Fas Ligand-Induced Apoptosis as a Mechanism of Immune Privilege , 1995, Science.

[15]  T. Berg,et al.  Mutations in the E2‐PePHD and NS5A region of hepatitis C virus type 1 and the dynamics of hepatitis C viremia decline during interferon alfa treatment , 2000, Hepatology.

[16]  Toshiaki Maruyama,et al.  Complete Replication of Hepatitis C Virus in Cell Culture , 2005, Science.

[17]  G. Trinchieri,et al.  Mechanism of Suppression of Cell-Mediated Immunity by Measles Virus , 1996, Science.

[18]  L. Beretta,et al.  Activation of the N-Ras–PI3K–Akt-mTOR Pathway by Hepatitis C Virus: Control of Cell Survival and Viral Replication , 2005, Journal of Virology.

[19]  L. Gooding,et al.  Adenoviral inhibitors of apoptotic cell death. , 2002, Virus research.

[20]  C. Ware,et al.  The adenovirus E3-10.4K/14.5K complex mediates loss of cell surface Fas (CD95) and resistance to Fas-induced apoptosis , 1997, Journal of virology.

[21]  M. Sato,et al.  Characterization of HCV structural proteins expressed in various animal cells. , 1994, Intervirology.

[22]  D. Burton,et al.  Robust hepatitis C virus infection in vitro. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[23]  R. K Srivastava.  TRAIL/Apo-2L: mechanisms and clinical applications in cancer. , 2001, Neoplasia.

[24]  I. Jeremias,et al.  Cooperation of betulinic acid and TRAIL to induce apoptosis in tumor cells , 2004, Oncogene.

[25]  Ron Kwok,et al.  A Mini-Surge on the Ryder Glacier, Greenland, Observed by Satellite Radar Interferometry , 1996, Science.

[26]  J. Abraham,et al.  Hepatitis C virus core, NS3, NS5A, NS5B proteins induce apoptosis in mature dendritic cells , 2005, Journal of medical virology.

[27]  D. Vlahov,et al.  Persistence of viremia and the importance of long‐term follow‐up after acute hepatitis C infection , 1999, Hepatology.

[28]  F. Martinon,et al.  Three Adenovirus E3 Proteins Cooperate to Evade Apoptosis by Tumor Necrosis Factor-related Apoptosis-inducing Ligand Receptor-1 and -2* , 2001, The Journal of Biological Chemistry.

[29]  M. Lutter,et al.  Biochemical pathways of caspase activation during apoptosis. , 1999, Annual review of cell and developmental biology.

[30]  O. Hino,et al.  Hepatitis C Virus Core Protein Interacts with 14-3-3 Protein and Activates the Kinase Raf-1 , 2000, Journal of Virology.

[31]  C. Hahn,et al.  The HCV core protein acts as a positive regulator of fas-mediated apoptosis in a human lymphoblastoid T cell line. , 2000, Virology.

[32]  S. Polyak,et al.  Hepatitis C virus--cell interactions and their role in pathogenesis. , 2003, Clinics in liver disease.

[33]  A. McMichael,et al.  Virus infections: escape, resistance, and counterattack. , 2001, Immunity.

[34]  K. Ishak,et al.  Long‐term clinical and histopathological follow‐up of chronic posttransfusion hepatitis , 1991, Hepatology.

[35]  P. Scheurich,et al.  TNF-related apoptosis inducing ligand (TRAIL) and its receptors in tumor surveillance and cancer therapy , 2002, Apoptosis.

[36]  J. Silver,et al.  Replication of Subgenomic Hepatitis C Virus Rnas in a Hepatoma Cell Line , 1999 .

[37]  K. Schulze-Osthoff,et al.  Apoptosis in hepatitis C virus infection , 2003, Cell Death and Differentiation.

[38]  Kyu-Jin Park,et al.  Hepatitis C Virus Core Protein Potentiates TNF-α-Induced NF-κB Activation through TRAF2-IKKβ-Dependent Pathway , 2001 .

[39]  M A Gerber,et al.  The natural history of community-acquired hepatitis C in the United States. The Sentinel Counties Chronic non-A, non-B Hepatitis Study Team. , 1992, The New England journal of medicine.

[40]  S. Fulda,et al.  Inhibition of TRAIL-induced apoptosis by Bcl-2 overexpression , 2002, Oncogene.

[41]  W. Hong,et al.  The hepatitis C virus core protein interacts with NS5A and activates its caspase-mediated proteolytic cleavage. , 2001, Virology.

[42]  C. Benedict,et al.  To kill or be killed: viral evasion of apoptosis , 2002, Nature Immunology.

[43]  A. Ashkenazi,et al.  Apo2L/TRAIL and its death and decoy receptors , 2003, Cell Death and Differentiation.

[44]  M. Grütter,et al.  Caspases: key players in programmed cell death. , 2000, Current opinion in structural biology.

[45]  Dean P. Jones,et al.  Prevention of Apoptosis by Bcl-2: Release of Cytochrome c from Mitochondria Blocked , 1997, Science.

[46]  M. St. Claire,et al.  Mutations that permit efficient replication of hepatitis C virus RNA in Huh-7 cells prevent productive replication in chimpanzees , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[47]  R. Bartenschlager,et al.  Production of infectious hepatitis C virus in tissue culture from a cloned viral genome , 2005, Nature Medicine.

[48]  G. Kroemer,et al.  The mitochondrial death/life regulator in apoptosis and necrosis. , 1998, Annual review of physiology.

[49]  D. Pessayre,et al.  Hepatitis C virus core protein inhibits microsomal triglyceride transfer protein activity and very low density lipoprotein secretion: a model of viral‐related steatosis , 2002, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[50]  D. R. Taylor,et al.  Inhibition of the interferon-inducible protein kinase PKR by HCV E2 protein. , 1999, Science.

[51]  D. Noh,et al.  Functional screening of genes suppressing TRAIL-induced apoptosis: distinct inhibitory activities of Bcl-XL and Bcl-2 , 2003, British Journal of Cancer.

[52]  Ingo Schmitz,et al.  Differential Modulation of Apoptosis Sensitivity in CD95 Type I and Type II Cells* , 1999, The Journal of Biological Chemistry.

[53]  W. Cavenee,et al.  The potential of TRAIL for cancer chemotherapy , 2001, Apoptosis.

[54]  M. Lai,et al.  Detection of a Novel Unglycosylated Form of Hepatitis C Virus E2 Envelope Protein That Is Located in the Cytosol and Interacts with PKR , 2002, Journal of Virology.

[55]  H. Hotta,et al.  Suppression of actinomycin D-induced apoptosis by the NS3 protein of hepatitis C virus. , 1996, Biochemical and biophysical research communications.

[56]  P. Romano,et al.  Protein Synthesis and Endoplasmic Reticulum Stress Can Be Modulated by the Hepatitis C Virus Envelope Protein E2 through the Eukaryotic Initiation Factor 2α Kinase PERK , 2003, Journal of Virology.

[57]  H J Alter,et al.  An assay for circulating antibodies to a major etiologic virus of human non-A, non-B hepatitis. , 1990, Science.

[58]  M. Lucassen,et al.  Yellow Fever Virus Replicons as an Expression System for Hepatitis C Virus Structural Proteins , 2003, Journal of Virology.

[59]  P. Marcellin,et al.  Hepatitis C: the clinical spectrum of the disease. , 1999, Journal of hepatology.

[60]  J. Kerr,et al.  Apoptosis, lymphocytotoxicity and the containment of viral infections. , 1985, Medical hypotheses.

[61]  S. Greive,et al.  Expression of the hepatitis C virus structural proteins in mammalian cells induces morphology similar to that in natural infection , 2002, Journal of viral hepatitis.

[62]  F. Shibasaki,et al.  Inhibition of Cytochrome c Release in Fas-mediated Signaling Pathway in Transgenic Mice Induced to Express Hepatitis C Viral Proteins* , 2001, The Journal of Biological Chemistry.