1. S 144 (VIROLOGY)
Lecture 1: Introduction
Parungao-Balolong 2011-2012
Friday, June 17, 2011

2. Skills, Values and Outputs
Listening, Writing & Communication Skills
Openness and Appreciation of Old &
Advancing Ideas
Objectivity & Critical Thinking
Parungao-Balolong 2011-2012
Friday, June 17, 2011

3. Lecture Outline
Introduction to Virology
History
Reasons for the Study of Virology
Origin & Evolution of Viruses
Parungao-Balolong 2011-2012
Friday, June 17, 2011

4. Introduction to Virology
VIROLOGY
scientific study of viruses and the disease they cause
VIRUSES
an infective agent typically consists of nucleic acid in
a protein coat
too small to be seen by light microscopy
multiply within living cells of host (obligate parasite)
filterable
Parungao-Balolong 2011-2012
Friday, June 17, 2011

5. Introduction to Virology
Jane Flint Principles of Virology, 2004
Parungao-Balolong 2011-2012
Friday, June 17, 2011

6. Introduction to Virology
Viruses challenge the way we define LIFE:
they do not respire
they do not display irritability
they do not move
they do not “grow”
WHAT THEY DO: they reproduce and adapt to new
hosts
Parungao-Balolong 2011-2012
Friday, June 17, 2011

7. Strategies for Survival
Genomes are packaged inside a particle (transmission)
Genome contains all information needed for infection
cycle (attachment to release)
Establishment in a host population
Parungao-Balolong 2011-2012
Friday, June 17, 2011

8. History of Virology
Dmitri Iosifovich Ivanowsky
(1892)
Martinus Beijerink (1898)
Filterable agent: Tobacco
Mosaic Virus
Parungao-Balolong 2011-2012
Friday, June 17, 2011

9. History of Virology
Freidrich Loeffler & Paul
Frosch (1898)
Foot & Mouth Disease Virus
Parungao-Balolong 2011-2012
Friday, June 17, 2011

10. History of Virology
Walter Reed (1899)
Yellow fever: transmission
by insect vectors
Parungao-Balolong 2011-2012
Friday, June 17, 2011

11. History of Virology
VIRUSES AND
ONCOGENESIS
Ellerman and Bang
(1908)
Chicken leukemia
Peyton Rous (1911)
Rous Sarcoma
virus Parungao-Balolong 2011-2012
Friday, June 17, 2011

12. History of Virology
Bacteriophages Era
Frederick Twort (1915)
discovery of phages
Felix D’ Herelle (1917)
role in immunity
Parungao-Balolong 2011-2012
Friday, June 17, 2011

13. History of Virology
Wendell Stanley (1935): crystallization of TMV
Delbruck (1940s): modern molecular biology and virology
Lwoff (1949): discovery of lysogeny
Enders et al., (1949): poliovirus and tissue culture/plaque
assays
1980s: Immunology and PCR technology was introduced as
well as gene therapy and bioterrorism
Parungao-Balolong 2011-2012
Friday, June 17, 2011

14. Why Study Viruses?
Some Viruses Cause Disease
Rabies
Common Cold
Smallpox
HIV
Parungao-Balolong 2011-2012
Friday, June 17, 2011

15. Why Study Viruses?
Some Viruses Cause Disease
Pepper Mottle Virus Cauliflower Mosaic Virus Rice Tungro Virus
Papaya Ringspot Virus
Tobacco Mosaic Virus Parungao-Balolong 2011-2012
Friday, June 17, 2011

16. Why Study Viruses?
Some Viruses Cause Disease
Foot & Mouth Disease Classical Swine Fever Porcine Reproductive & Respiratory Syndrome
(PRRS)
Ebola
Avian Flu Parungao-Balolong 2011-2012
Friday, June 17, 2011

17. Why Study Viruses?
Some Viruses Cause Disease
AH1N1
Parungao-Balolong 2011-2012
Friday, June 17, 2011

18. Why Study Viruses?
Some Viruses are Useful
Phage Typing of Bacteria
e.g. Salmonella spp.
classified into strains on the
basis of the spectrum of
phages to which they are
susceptible
advantage: Epidemiology
Parungao-Balolong 2011-2012
Friday, June 17, 2011

19. Why Study Viruses?
Some Viruses are Useful
Sources of Enzymes
RNA polymerase (T7 phage)
Genetic Pesticides
gene from baculovirus
against worms
Parungao-Balolong 2011-2012
Friday, June 17, 2011

20. Why Study Viruses?
Some Viruses are Useful
Anti-Bacterial Agents
Extrasomatic SARS virus
(e.g. NORWEX)
Anti-Cancer Agents
Herpes Simplex Virus
Vaccinia Virus
Destroy tumor cells not normal
cells Parungao-Balolong 2011-2012
Friday, June 17, 2011

21. Why Study Viruses?
Some Viruses are Useful
Gene Vector for Protein Production
baculovirus, adenovirus
vaccine component
Gene Vector for Treatment of Genetic
Diseases
retrovirus
immunodeficient cases Parungao-Balolong 2011-2012
Friday, June 17, 2011

22. Why Study Viruses?
Virus Studies Have Contributed to Knowledge
Hershey and Chase experiment (T2 phage)
Parungao-Balolong 2011-2012
Friday, June 17, 2011

23. Why Study Viruses?
Virus Studies Have Contributed to Knowledge
Characterization of enhancers (genes of Simian SV 40)
Characterization of transcription factors and localization of protein signal (genes of Simian
SV 40)
Parungao-Balolong 2011-2012
Friday, June 17, 2011

24. Why Study Viruses?
Virus Studies Have Contributed to Knowledge
Discovery of introns (adenovirus)
Role of cap structure at 5’ end of eukaryotic mRNA (vaccinia
and reovirus)
discovery of internal ribosomal entry site (RNA of poliovirus)
discovery of RNA pseudoknot (turnip yellow mosaic virus)
Parungao-Balolong 2011-2012
Friday, June 17, 2011

25. Nature of Viruses
Viruses are Small Particles
Parungao-Balolong 2011-2012
Friday, June 17, 2011

26. Nature of Viruses
Viruses Have Genes virus code efficiently
virus use host cell multifunctional
proteins
Parungao-Balolong 2011-2012
Friday, June 17, 2011

27. Nature of Viruses
Viruses are Parasites
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Friday, June 17, 2011

28. Origin & Evolution of Viruses
Origin & Evolution of Viruses
Parungao-Balolong 2011-2012
Friday, June 17, 2011

29. Origin & Evolution of Viruses
Origin & Evolution of Viruses
Parungao-Balolong 2011-2012
Friday, June 17, 2011