Excerpt

Chronic hepatitis C is a serious public health problem and a disease burden in many parts of the world. The discovery of the causative agent, hepatitis C virus (HCV), in 1989 has initiated an almost unparalleled research activity in academic and pharmaceutical-industry laboratories over the ensuing years. This book aims to provide a state-of-the-art account of recent advances in the molecular and cellular biology, immunology and pathogenesis of HCV. It also aspires to discuss new strategies as well as outstanding issues for future research.

Hepatitis C has been dubbed the “silent epidemic” because it is generally asymptomatic for decades after infection; its victims often are unaware of the infection until it is too late for therapy. What is the genetic makeup and molecular features that make HCV such a “silent” yet deadly assassin? This question, in fact, is the premise by which this monograph was prepared – it was an attempt to decode the secrets of HCV, one viral gene at a time. To that end, we assembled a team of highly regarded experts from different disciplines who have prepared 16 chapters on various aspects of HCV, including the HCV genome and the role(s) of each viral gene product within the context of the viral life cycle, host interactions, and regulation of host antiviral defense and adaptive immunity.

Contents

• Contributors
• Preface
  Seng-Lai Tan, Ph.D.
• Introduction
  David R. Gretch.
• 1. HCV Genome and Life Cycle
  Stéphane Chevaliez and Jean-Michel Pawlotsky.
  • HCV Genome Organization and Function
  • HCV Genome Structure and Organization
  • Characteristics and Functions of HCV Proteins
  • The HCV Lifecycle
  • Structure of HCV Virions
  • Conclusion
  • References
• 2. HCV 5′ and 3′UTR: When Translation Meets Replication
  Stephanie T Shi and Michael M C Lai.
  • Introduction
  • Structural and Functional Components of the HCV RNA
  • HCV Translation
  • HCV RNA Replication
  • Regulation of HCV Translation and Replication
  • Perspectives
  • References
• 3. Assemble and Interact: Pleiotropic Functions of the HCV Core Protein
  Stephen J Polyak, Kevin C Klein, Ikuo Shoji, Tatsuo Miyamura, and Jaisri R Lingappa.
  • Introduction
  • The Core of the Problem
  • The Role of HCV Core in Capsid Assembly
  • Sub-Cellular Targeting of HCV Core
  • Post-Translational Modifications of HCV Core
  • HCV Core-Host Interactions
  • References
• 4. HCV Glycoproteins: Assembly of a Functional E1–E2 Heterodimer
  Muriel Lavie, Anne Goffard, and Jean Dubuisson.
  • Introduction
  • Biogenesis of HCV Envelope Glycoproteins
  • Role of HCV Envelope Glycoproteins in Virus Entry
  • Conclusion
  • Future Trends
  • References
• 5. HCV NS2/3 Protease
  Sarah Welbourn and Arnim Pause.
  • Introduction
  • NS2/3 Catalytic Cleavage
  • Role of NS2/3 Cleavage in Viral Replication
  • Roles of Cleaved NS2
  • Conclusions
  • References
• 6. HCV NS3-4A Serine Protease
  Chao Lin.
  • Introduction
  • Biological Functions
  • Three Dimensional Structures
  • Assays for the HCV NS3-4A Serine Protease
  • A Drug Discovery Target
  • Preclinical Studies and Clinical Development
  • Conclusions and Future Directions
  • References
• 7. HCV Helicase: Structure, Function, and Inhibition
  David N Frick.
  • Introduction
  • Structure of HCV Helicase
  • Mechanism of Action
  • HCV Helicase Inhibitors
  • Conclusions and Future Directions
  • References
• 8. HCV NS4B: From Obscurity to Central Stage
  Ella H Sklan and Jeffrey S Glenn.
  • Introduction
  • Proteolytic Generation of NS4B
  • Subcellular Localization and Topology
  • NS4B and Lipid Rafts
  • The Immunological Effects of NS4B
  • Modulation of Ns5bs' RNA-Dependent RNA Polymerase Activity
  • Effects of NS4B on Translation
  • "Membranous Web" Formation
  • Modulation of ER Functions
  • Malignant Transformation
  • NS4B Features That May Underlie the Mechanisms of the Above Functions
  • Future Directions
  • Future Directions
  • References
• 9. HCV NS5A: A Multifunctional Regulator of Cellular Pathways and Virus Replication
  Yupeng He, Kirk A Staschke, and Seng-Lai Tan.
  • Introduction
  • Structural Features and Subcellular Localization of NS5A
  • NS5A Phosphorylation: A Functional Role or Red Herring?
  • Emerging Role of NS5A in HCV Replication
  • NS5A as a Viral Interceptor of Cellular Pathways
  • Concluding Remarks
  • References
• 10. Biochemical Activities of the HCV NS5B RNA-Dependent RNA Polymerase
  C T Ranjith-Kumar and C Cheng Kao.
  • Introduction
  • Expression of NS5B
  • Structural Features of HCV NS5B
  • Catalytic Pocket
  • Activities of NS5B
  • De novo Synthesis and Primer Extension
  • Mutational Analysis
  • Terminal Nucleotidyl Transferase (TNTase) Activity
  • Template Switch
  • Interaction with Other HCV Nonstructural Proteins
  • Conclusion and Future Trends
  • References
• 11. HCV Replicon Systems
  Keril J Blight and Elizabeth A Norgard.
  • Introduction
  • Development of HCV Replicons
  • Identification of Adaptive Mutations
  • Generation of Replicons from Other HCV Isolates
  • Development of Alternative Replicon Derivatives
  • Cell Lines Permissive for HCV Replication
  • Applications of the HCV Replicon System
  • Inhibition of Replicon Replication
  • Concluding Remarks
  • References
• 12. Animal Models for HCV Study
  Linda B Couto and Alexander A Kolykhalov.
  • Chimpanzee Model
  • Transgenic Mouse Models
  • Xenograft Models
  • Small Non-Human Primate Models
  • Summary and Conclusions
  • References
• 13. HCV Regulation of Host Defense
  D Spencer Carney and Michael Gale Jr.
  • Introduction
  • Innate Intracellular Immune Defenses
  • ISG Products Have Antiviral Functions
  • Cross-Talk Between Innate and Adaptive Immune Defenses
  • IFN-γ Activation of the Antiviral Response
  • Hepatic Defenses Are Triggered by HCV
  • Triggering the Host Response to HCV Infection
  • Regulation and Evasion of the Host Response by HCV
  • HCV Regulation of IFN Signaling
  • Regulation of ISG Expression or Function
  • Viral Genetics Impact the Host Response to HCV Infection
  • Exogenous Induction of Antiviral Hepatic Defenses
  • The HCV/Host Interface Model of Viral Evasion
  • References
• 14. Regulation of Adaptive Immunity by HCV
  Xiao-Song He.
  • Introduction
  • Adaptive Immunity to HCV: A Failure in Most Patients
  • Dendritic Cells–Are They Infected by HCV?
  • Interference of Host Cell Functions by HCV
  • Regulatory T Cells in HCV Infection
  • Immune Cells and Immune Responses in the Liver
  • Conclusion
  • References
• 15. Recombinant Vesicular Stomatitis Virus (VSV) and Other Strategies in HCV Vaccine Designs and Immunotherapy
  Ayaz M Majid and Glen N Barber.
  • Introduction
  • Classical Strategies in Viral Vaccines
  • Studies of Recombinant HCV Protein Sub-Units in Chimpanzees
  • Efficacy of Recombinant DNA Approaches in Generating HCV Immunity
  • Hepatitis C Virus-like Particles
  • VSV as a Safe and Potent Vector for Generating Immunity against Viral Pathogens
  • VSV-HCV Pseudotypes as a Prelude to Recombinant VSV in HCV Immuno-Intervention
  • Replication Competent and Defective Recombinant VSV as a Vaccine Strategy to Generate Immune Responses
  • Recombinant VSV Vaccine Studies
  • VSV Expressing HCV Core, E1 and E2 Structural Proteins as a Potential Vaccine and Immunotherapeutic Strategy against HCV Infection
  • Conclusions
  • Future Trends
  • References
• 16. Development of an Infectious HCV Cell Culture System
  Takaji Wakita and Takanobu Kato.
  • Introduction
  • A Case of Fulminant Hepatitis Associated with HCV
  • Sequence Analysis of JFH-1
  • Preferential Processing for Core Protein of JFH-1
  • Replication Capacity of JFH-1 as a Subgenomic Replicon
  • Construction of Full-Length JFH-1 cDNA
  • Replication of Full-Length JFH-1 RNA in Huh7 Cells
  • Infectivity of Secreted Viral Particles from JFH-1 Transfected Cells
  • Neutralization of JFH-1 Infectivity by CD81 Antibody and Patient Sera
  • In Vivo Infectivity of JFH-1 Culture Medium
  • Permissive Cells for JFH-1 Infection
  • Summary and Concluding Remarks
  • References