Transcript Intro -2015x
Slide 1
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 2
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 3
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 4
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 5
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 6
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 7
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 8
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 9
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 10
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 11
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 12
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 2
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 3
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 4
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 5
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 6
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 7
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 8
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 9
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 10
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 11
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Slide 12
Viral structure, classification and
replication
Deborah E. Sullivan, Ph.D.
Department of Microbiology and
Immunology
[email protected]
Introduction to Medical Virology
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy
Viral Structure and Classification
Learning objectives:
At the end of this learning module you will be able to:
• Describe the structure of the viral particle
• List the different types of viral genomes
• Explain the advantages and disadvantages of viral
envelopes
• Describe each step of the infectious cycle
• Explain the strategies employed by viruses for gene
expression
• Identify the cellular factors required for replication of all
viruses
• Classify several major human pathogens
We live and prosper in a literal cloud of viruses
• Viruses infect all living things
• We eat and breathe billions of virions regularly
• The 1013 human cells are outnumbered 10-fold by bacteria and
100-fold by viruses.
We carry viral genomes as part of our
own genetic material. (Syncytin is a
captive retroviral envelope protein
involved in human placental
morphogenesis. Mi et al. Nature. 2000)
An enteric virus can replace the
beneficial function of commensal
bacteria. Kernbauer et al. Nature 2014.
What is a virus?
A virus is a small infectious agent that replicates
only inside the living cells of other organisms.
Viruses vary in size
What do viruses look like?
Papilloma virus
Poliovirus
Herpesvirus
SARS virus
Rotavirus
Hepatitis B virus
Adenovirus
Influenza virus
Pox virus
All Viruses follow this three-part strategy….
1. They have a nucleic acid genome packaged in a proteinaceous
particle
– This particle is the vehicle for transmission of the viral genome from host to host
– The particle is a delivery device, but it is not alive
2. The viral genome contains the information to initiate and
complete an infectious cycle within a susceptible and permissive
cell
An infectious cycle allows attachment and entry of the particle, decoding of genomic
information, translation of viral mRNA by host ribosomes, genome replication, assembly
and release of particles containing the genome.
3. All viral genomes are able to establish themselves in a host
population
This three-part strategy achieves one goal:
SURVIVAL
I. Structure
II. Classification
III. Replication cycle
IV. Pathogenesis
V.
Prevention
VI. Diagnosis
VII. Therapy