How Pathogenic Viruses Think: Making Sense of Virology

170 Pages·2012·0.25 MB·English

by  Lauren Sompayrac

PATHOGENIC VIRUSES
how think
Making Sense of Virology
second edition
Lauren Sompayrac, PhD
Retired Professor
Department of Molecular, Cellular, and
Developmental Biology
University of Colorado
Boulder, Colorado
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Executive Publisher: Christopher Davis Composition: Jason Miranda, Spoke & Wheel
Managing Editor: Kathy Richardson Cover Design: Scott Moden
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Library of Congress Cataloging-in-Publication Data
Sompayrac, Lauren.
How pathogenic viruses think : making sense of virology / Lauren Sompayrac. — 2nd ed.
p. ; cm.
Rev. ed. of: How pathogenic viruses work / Lauren Sompayrac. c2002.
Includes index.
ISBN 978-1-4496-4579-3 — ISBN 1-4496-4579-8
I. Sompayrac, Lauren. How pathogentic viruses work. II. Title.
[DNLM: 1. Viruses. 2. Virus Diseases. QW 160]

616.9'101—dc23
2012003777
6048
Printed in the United States of America
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DEDICATION
I dedicate this book to my outstanding editor, Chris Davis,
who shares my belief that although science is serious, it
should also be fun. Thank you, Chris!
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Contents
Dedication iii
Acknowledgments xi
Introduction xiii
Part I: Fathoming the Mind of a Virus 1
Chapter 1 The Organizing Principle 3
Background ........................................................................................................... 3
Four Problems Every Virus Must Solve ......................................................................... 4
Consistent Solutions ................................................................................................ 5
Viral Pathogenesis ................................................................................................... 5
Fathoming the Mind of a Virus ................................................................................... 5
GENERAL PRINCIPLES ........................................................................................... 6
Chapter 2 Host Defenses 7
Background ........................................................................................................... 7
Barrier Defenses ..................................................................................................... 8
The Innate Defense System ........................................................................................ 9
The Adaptive Immune System .................................................................................. 10
GENERAL PRINCIPLES ......................................................................................... 12
Chapter 3 The Interferon Defense System 13
Background ......................................................................................................... 13
Viral Detection ..................................................................................................... 13
Interferon Function ................................................................................................ 15
Sequential Production of IFN- and IFN- ................................................................... 16
Viral Evasion of the Interferon Defense ....................................................................... 17
GENERAL PRINCIPLES ......................................................................................... 18
v
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vi Contents
Part II: The Bug Parade 19
Viruses We Inhale
Chapter 4 Influenza: A “Bait-and-Switch” Virus 21
Background ......................................................................................................... 21
Influenza Virus Infection ......................................................................................... 21
Influenza Virus Reproduction ................................................................................... 23
Evading Host Defenses ........................................................................................... 26
How Influenza Viruses Spread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Influenza-Associated Pathology ................................................................................ 29
The Interviewer’s Summary ..................................................................................... 30
GENERAL PRINCIPLES ......................................................................................... 31
THOUGHT QUESTIONS ......................................................................................... 31
Chapter 5 Rhinovirus: A Virus That Surrenders 33
Background ......................................................................................................... 33
A Rhinovirus Infection ........................................................................................... 33
Rhinovirus Reproduction ........................................................................................ 34
Evading Host Defenses ........................................................................................... 35
Viral Spread ........................................................................................................ 36
Pathological Consequences of a Rhinoviral Infection ...................................................... 36
The Interviewer’s Summary ..................................................................................... 37
GENERAL PRINCIPLES ......................................................................................... 38
THOUGHT QUESTIONS ......................................................................................... 38
Chapter 6 Measles: A “Trojan Horse” Virus 39
Background ......................................................................................................... 39
Measles Virus Infection ........................................................................................... 39
Measles Virus Reproduction .................................................................................... 41
Evading Host Defenses ........................................................................................... 42
Measles Virus Transmission ..................................................................................... 43
The Pathological Consequences of a Measles Infection .................................................... 44
The Interviewer’s Summary ..................................................................................... 45
GENERAL PRINCIPLES ......................................................................................... 46
THOUGHT QUESTIONS ......................................................................................... 46
REVIEW 1 A Comparison of Respiratory Viruses .................................................................. 47
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Contents vii
Viruses We Eat
Chapter 7 Rotavirus: An Undercover Virus 49
Background ......................................................................................................... 49
A Rotavirus Infection ............................................................................................. 50
Viral Reproduction ................................................................................................ 50
Evading Host Defenses ........................................................................................... 51
How Rotavirus Spreads .......................................................................................... 52
The Pathological Consequences of a Rotavirus Infection .................................................. 53
The Interviewer’s Summary ..................................................................................... 53
GENERAL PRINCIPLES ......................................................................................... 54
THOUGHT QUESTIONS ......................................................................................... 54
Chapter 8 Adenovirus: A Virus With a Time Schedule 55
Background ......................................................................................................... 55
An Enteric Adenovirus Infection ............................................................................... 56
Adenoviral Reproduction ........................................................................................ 57
Replication of Adenoviral DNA ................................................................................ 57
How Does Adenovirus Evade Host Defenses? .............................................................. 59
How Do Enteric Adenoviruses Spread? ....................................................................... 61
Pathogenic Consequences of an Enteric Adenovirus Infection ........................................... 61
The Interviewer’s Summary ..................................................................................... 61
GENERAL PRINCIPLES ......................................................................................... 63
THOUGHT QUESTIONS ......................................................................................... 63
Chapter 9 Hepatitis A: A Virus That Detours 65
Background ......................................................................................................... 65
How Does Hepatitis A Virus Infect Its Host? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
How Does Hepatitis A Virus Reproduce? ..................................................................... 67
How Does Hepatitis A Virus Evade Host Defenses? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
How Does Hepatitis A Virus Spread? ......................................................................... 68
Viral Pathogenesis ................................................................................................. 69
The Interviewer’s Summary ..................................................................................... 70
GENERAL PRINCIPLES ......................................................................................... 70
THOUGHT QUESTIONS ......................................................................................... 70
REVIEW 2 A Comparison of Enteric Viruses ......................................................................... 71
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viii Contents
Viruses We Get From Mom
Chapter 10 Hepatitis B: A Decoy Virus 73
Background ......................................................................................................... 73
How Does Hepatitis B Virus Infect Its Target Cells? ........................................................ 73
How Does Hepatitis B Virus Reproduce? ..................................................................... 74
How Does Hepatitis B Virus Evade Host Defenses? ........................................................ 75
How Does Hepatitis B Virus Spread? .......................................................................... 76
Pathogenesis ........................................................................................................ 77
The Interviewer’s Summary ..................................................................................... 77
GENERAL PRINCIPLES ......................................................................................... 78
THOUGHT QUESTIONS ......................................................................................... 78
Chapter 11 Hepatitis C Virus: An Escape Artist 79
Background ......................................................................................................... 79
A Hepatitis C Virus Infection .................................................................................... 79
Viral Reproduction ................................................................................................ 80
Viral Evasion ....................................................................................................... 80
How Does Hepatitis C Virus Spread? ......................................................................... 81
Pathological Consequences of a Hepatitis C Infection ..................................................... 82
The Interviewer’s Summary ..................................................................................... 82
GENERAL PRINCIPLES ......................................................................................... 83
THOUGHT QUESTIONS ......................................................................................... 83
Chapter 12 HTLV-I: A Tribal Virus 85
Background ......................................................................................................... 85
An HTLV-I Infection .............................................................................................. 86
Viral Reproduction ................................................................................................ 86
How Does HTLV-I Evade Host Defenses? .................................................................... 87
How HTLV-I Spreads ............................................................................................. 88
Viral Pathogenesis ................................................................................................. 89
The Interviewer’s Summary ..................................................................................... 89
GENERAL PRINCIPLES ......................................................................................... 90
THOUGHT QUESTIONS ......................................................................................... 90
REVIEW 3 A Comparison of Vertically Transmitted Viruses ................................................... 91
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Contents ix
Viruses We Get By Intimate Physical Contact
Chapter 13 HIV-1: An Urban Virus 93
Background ......................................................................................................... 93
How Does HIV-1 Infect Its Hosts? .............................................................................. 94
Viral Reproduction ................................................................................................ 94
Viral Evasion Tactics .............................................................................................. 95
How HIV-1 Spreads ............................................................................................... 97
The Pathological Consequences of an HIV-1 Infection ..................................................... 99
The Interviewer’s Summary .................................................................................... 100
GENERAL PRINCIPLES ........................................................................................ 101
THOUGHT QUESTIONS ........................................................................................ 101
Chapter 14 Herpes Simplex: A Virus That Hides 103
Background ........................................................................................................ 103
Infection by Herpes Simplex Virus ............................................................................ 104
Viral Reproduction ............................................................................................... 104
Evasion of Host Defenses ....................................................................................... 105
Herpes Simplex Virus’ Strategy for Viral Spread ........................................................... 107
Pathogenesis ....................................................................................................... 108
The Interviewer’s Summary .................................................................................... 109
GENERAL PRINCIPLES ........................................................................................ 110
THOUGHT QUESTIONS ........................................................................................ 110
Chapter 15 Human Papillomavirus: A Very Quiet Virus 111
Background ........................................................................................................ 111
Infection ............................................................................................................ 112
Viral Reproduction ............................................................................................... 113
Viral Evasion Tactics ............................................................................................. 114
Viral Spread ....................................................................................................... 114
HPV-Associated Pathology ..................................................................................... 115
The Interviewer’s Summary .................................................................................... 116
GENERAL PRINCIPLES ........................................................................................ 117
THOUGHT QUESTIONS ........................................................................................ 117
REVIEW 4 Viruses Which Establish Long-Term Infections .................................................... 119
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