Download presentation
Presentation is loading. Please wait.
1
Viruses Individual Viruses = Virion Not cells – nonliving
Size μm Bacterial Viruses = Bacteriophage T 4
2
Viral Genome Double Strand or Single Strand DNA or RNA
Most Genomes Linear Overlapping genes Human Papillomavirus
3
Protein Coat Capsid, Coat, Shell Capsomer - Individual Proteins
Self Assembly Nucleocapsid
4
Viral Symmetry Helical Icosahedral 20 faces, 12 vertices
5
Icosahedral Subunits
6
Tobacco Mosaic Virus Herpes Simplex Virus
7
Enveloped Virus
8
Complex Virus T 4 Bacteriophage
9
Enzymes in Viruses Reverse Transcriptase Lysozyme RNA Polymerase
Neuraminidase
10
Viral Host Living Cells Animal Host Cell Culture Tissue Culture
Monolayer
11
Cell Line Primary Culture Line Transformation Permanent Cell line
Viruses Mutagen Permanent Cell line HELA –Henrietta Lacks
12
Quantification of Viruses
Plaque Assay – Bacteria Efficiency of Plating Animal Infectivity Methods End Point Dilution
13
Bacteriophage Plaques
14
Plaques in Tissue Culture Monolayer
15
Viral Replication Attachment Penetration
17
1. Production of Early Proteins Replication of Nucleic Acids
Synthesis 1. Production of Early Proteins Replication of Nucleic Acids 2. Production of Late Proteins Viral Coat
18
Assembly Release
19
One-step Growth Curve Latent Period
20
Some Host Cells Use Restriction Enzymes to Destroy DNA Viruses
Some Viruses Can Modify Their Genome’s Restriction Sites for Protection
21
Baltimore Classification Scheme
David Baltimore, Howard Temin, Renato Dulbecco 1975 Reverse transciptase Retro virus 6 Classes based on DNA→RNA→Protein 7th Class Hepadnaviruses added
22
6 Classes of Viruses Class I DS DNA Herpes virus Class II SS DNA ØX 174 Class III DS RNA Reovirus –rotavirus Class IV +SS RNA Polio Class V -SS RNA Influenza Class VI SS RNA Retrovirus Others?
23
HEPADNAVIRUS Class VII DS DNA virus Reverse transcriptase Use RNA intermediate Smallest genome 3-4 kb Hepatitis B
24
+/- SS RNA Viruses SS DNA Viruses DS Intermediates Reverse Transcriptase
25
Virulent Bacteriophage
Lytic T Phages T4, T7 DS DNA Head, Tail, Spikes Base Plate, Tail Fibers, Contractile Sheath Hydroxymethyl-cytosine
26
Lambda Best Known Virus? Can be Virulent or Temperate
Lysis or Lysogeny Becomes Prophage (Provirus) Gives Immunity to Host Specific Insertion Site
28
Maintenance of Lysogeny
Lambda Repressor -Lysogeny CRO Protein - Lysis Induction
29
Animal Viruses DNA Viruses RNA Viruses
30
Eukaryotic Host Types of Infections: Lytic Persistent Latent
Hepatitis A Herpes
31
Cancer Viruses Transformation Neoplasm Benign Malignant Metastasis
Oncogene
32
Retrovirus RNA Genome Reverse Transcriptase
DNA Copy Insert into Host Genome AIDS Acquired Immunodeficiency Syndrome HIV – Human Immunodeficiency Virus HIV
33
Subviral Entities Defective Viruses Parasitic? Helper Viruses
Satellite Viruses AAV – Adenovirus Associated Virus Specific Insertion Sites
34
Viroids Naked Circles SS RNA 246-375 Nucleotides Plant Diseases
Regulatory RNA -sRNA
35
Prions Infectious Proteins? Chaperone Protein Kuru Mad Cow Disease
Scrapies Creutzfeldt- Jakob Disease 11/21/2018
36
Prion Infectious Cycle
PrPc → PrPsc Infectious, Sporadic, or Inherited Prion Disease Mice with no PrPc are Normal?
37
Viruses Word List Virion Bacteriophage 28 –200 nm (0.2 μm) Genome
SS/DS RNA/DNA Capsid, Coat, Shell Capsomer Self-Assembly Nucleocapsid Viral Symmetry Helical Icosahedral Enveloped Viruses Complex Viruses Enzymes in Virion Reverse Transcriptase Lysozyme Viral Host Living Organisms Cell (Tissue) Culture Monolayer Primary Culture Line
38
Viruses 2 Transformation Permanent Cell Line Quantification of Viruses
Plaque Assay Efficiency of Plating Animal Infectivity Methods End Point Dilution Viral Reproduction Attachment Penetration Early Steps (Early Proteins) Replication of Nucleic Acids Synthesis of Proteins (Late) Assembly Release
39
Viruses 3 One-step Growth Curve Latent Period
Restriction/ Modification Restriction Enzymes Modification +/- SS RNA Viruses SS DNA Viruses DS Intermediates Reverse Transcriptase BACTERIAL VIRUSES Model Viruses Genetic Engineering RNA Bacteriophage +SS RNA Viruses MS2 “Male” Specific Phage
40
Viruses 4 4 Proteins4 Proteins Maturation, Coat, Lysis & RNA Replicase
Overlapping Genes SS DNA Icosahedral Phage ФX 174 DS DNA Phage – Lytic T7, T4 Head, Tail, Base Plate, Spikes, Tail Fibers, Contractile Sheath Hydoxymethylcytosine Temperate Bacteriophage Lambda
41
Viruses 5 Virulent – Temperate Lysogeny Prophage – Provirus Immunity
Lambda Repressor Cro protein Transposable Phage Insertion Elements Transposon Mu Phage – Mutator Animal Viruses Eukaryotic Hosts Lytic Infections Persistent Infections Latent Infections
42
Viruses 6 Cancer Transformation Neoplasm Benign Malignant Metastasis
Oncogene +SS RNA Viruses Rhinovirus Foot-and-Mouth Virus Poliovirus Polyprotein Viral Protease -SS RNA Virus Rhabdovirus RNA Dep. RNA Polymerase Influenza Segmented Genome DS RNA Virus Reovirus Rotavirus
43
Viruses 7 DNA Virus Papovavirus SV 40 Herpesviruses
Herpes simplex, Chickenpox, Shingles, Epstein-Barr, Burkitt’s Lymphoma Pox Virus Smallpox Adenovirus Retrovirus Reverse Transcriptase Acquired Immuno deficiency Syndrome – AIDS Viroids SS RNA Circles
44
Viruses 8 Prions “Mad Cow Disease” Kuru Scrapies
Creutzfeldt-Jakob Disease
Similar presentations
