Introduction to the viruses

Introduction to the viruses

1. Virology
Introduction to the viruses
Nathan Kikku Mubiru
Medical laboratory scientist (MLSO)

2. Edward Jenner
Vaccinations
Cowpox
cross protection against
small pox
Variola virus
Major
Blisters
Blindness
Death
Minor
Poxviridae
dsDNA

3. Viruses
Define
Classification
Group
NA
Family
-viridae
Genus
-virus
Species
Name

5. Host Affinity
Specific
Host
Cell type
General
Examples
Bacteriophage
Viroid (plant)

6. Host Range: Plants

7. Host Range: Bacteria

8. Host Range: Animals

9. Animal Virus Examples

10. Viral Culture
Culture
Bacteria
Chick Embryos
Cell/Tissue
Purified
Assays
Hemagglutination
Plaque

12. Viral Characteristics
Acellular
Infectious
Phases
Extracellular
Intracellular
Viron structure
Nucelocapsid
Capsid
NA
+/-Envelope

13. Viral Morphology
Size
10-400 nm
Structural
components
Nucleocapsid
Envelope (+/-)
Classifications
NA
ss or ds

14. Size

15. Viral Capsid
Function
Protect NA
Aids in transfer to host
Structure
Protein coat
Capsomere arrange
Helical
Polyhedral
Complex

16. Polyhedral Capsids

17. Capsomeres are capsid subunits

18. Naked vs. Enveloped Viruses

19. Viral Envelope
Presence
Enveloped
Naked (non-enveloped)
Location
Surrounds capsid
Source
Host plasma membrane
Nuclear membrane
Endoplasmic reticulum
Components
Phospholipid
Proteins
Glycoprotein spikes (+/-)
Examples
Influenza
Rabies
Herpes
HIV

20. Envelope Glycoprotein Spikes

21. Viral NA
DNA OR RNA
Shape
Circular
Linear
Number
One
Or more
Strands
ss
ds
+ or -if RNA

22. Viral Classification
dsDNA
Small pox
Herpes
Papilloma
ssDNA
Parvo
dsRNA
Rotavirus
+ssRNA
Polio
Rhino
Corona
-ssRNA
Measles, mumps
Rabies
Influenza
Retroviruses
HIV

23. Bacteriophage Life Cycle
Lytic
Attach and entry
Synthesis
Assembly
Lysis
Lysogenic
Attach and entry
NA in chromosome
Binary fission
Renters lytic phase
Synthesis
Assembly
Lysis

24. Lytic

25. Bacteriophage Lytic Cycle
animation

26. Lysogenic

27. Specialized
Transduction

28. Bacteriophage Cycle

29. Phage Cycle Summary

30. Viral Replication Differences

31. Viral Infections

32. Replication of Animal Viruses
Attach
Entry
Direct Penetration
Membrane fusion
Endocytosis
Uncoating
Synthesis
Assembly
Release

33. Viral Attachment

34. Direct

35. Endocytosis vs. Membrane Fusion

36. Release of Genome (uncoating)
Endosome formation
pH drop due to H+ pump
Fusion peptide to PM
Conformational change
Release of NA
Adenovirus uncoating
Influenza Virus

37. NA synthesis
dsDNA: usual replication (for most)
ssDNA
complementary strand
Normal replication
dsRNA
+ strand = mRNA
Template and copy
+ssRNA
+ strand = mRNA
Complimentary strand for
template
-ssRNA
Viral enzymes make + strand
Template for mRNA and -ss
Retroviruses
+ssRNA (mRNA to make DNA)
Reverse transcriptase
DNA is template for new
+ssRNA

39. DNA Virus Biosynthesis

40. RNA Virus

41. Retroviruses

42. Viral Assembly
DNA
Nucleus
Moves to cytoplasm
RNA
cytoplasm

43. Use of ER and Golgi
Herpes

44. Viral Release
Types
Budding
Acquire membranes
envelope
Exocytosis
Lysis
Latency

45. Budding

46. Viral Exocytosis

47. Viral Lysis

48. Viral Damage

49. Viral Transmission

50. Acute vs. Latent

51. Viral
Infections

53. Viruses and Cancer
Definitions
Oncogenes
Activation
Mutation
Transduction
Tumor
Types
Benign
Malignant
Characteristics
Examples
DNA
Adenovirus
Herpes
Poxviruses
Papoviruses
Hepadenaviruses
RNA
Retroviruses
HIV
HTLV

54. Immune Response
Adaptive Immunity

55. Anti-Viral Drugs
Attachment antagonists
Block attachment molecule
Arildone
Inhibit Uncoating
Neutralize acid environment
Amantadine
Rimantadine
Inhibit DNA/RNA synthesis
Activation by phosphorylation
of drug by viral kinases
Acyclovir
Gancyclovir

56. Prions
Infectious proteins
Structure
Insoluble
Beta pleated sheet
PrPc PrPsc
Affects NS
Fibrils
Vacuoles (spongy)
Examples
BSE
CJD
Scrapie
Kuru

57. Prion Production

58. Viral/Prion Related Diseases
ALZ
MS
Parkinsons
ALS
DM
RA
Hepatitis
SLE
Neoplasia

59. Other Proposed Viral Diseases

60. Questions?