Virology lecture 1 introduction

S 144 (VIROLOGY)Lecture 1: Introduction

Parungao-Balolong 2011-2012Friday, June 17, 2011

Skills, Values and Outputs

Listening, Writing & Communication Skills

Openness and Appreciation of Old & Advancing Ideas

Objectivity & Critical Thinking


Lecture Outline

Introduction to Virology

History

Reasons for the Study of Virology

Origin & Evolution of Viruses


Introduction to VirologyVIROLOGY

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)

filterableParungao-Balolong 2011-2012

Friday, June 17, 2011

Introduction to Virology

Parungao-Balolong 2011-2012

Jane Flint Principles of Virology, 2004


Introduction to VirologyViruses 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


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


History of Virology

Dmitri Iosifovich Ivanowsky (1892)

Martinus Beijerink (1898)

Filterable agent: Tobacco Mosaic Virus


History of Virology

Freidrich Loeffler & Paul Frosch (1898)

Foot & Mouth Disease Virus


History of VirologyWalter Reed (1899)

Yellow fever: transmission by insect vectors


History of VirologyVIRUSES AND ONCOGENESIS

Ellerman and Bang (1908)

Chicken leukemia

Peyton Rous (1911)

Rous Sarcoma virus


History of VirologyBacteriophages Era

Frederick Twort (1915)

discovery of phages

Felix D’ Herelle (1917)

role in immunity


History of VirologyWendell 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


Why Study Viruses?Some Viruses Cause Disease


Common Cold

Rabies

HIVSmallpox




Pepper Mottle Virus Cauliflower Mosaic Virus

Tobacco Mosaic Virus

Rice Tungro Virus

Papaya Ringspot Virus




Foot & Mouth Disease Classical Swine Fever

Avian Flu

Porcine Reproductive & Respiratory Syndrome (PRRS)

Ebola




AH1N1


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: EpidemiologyParungao-Balolong 2011-2012


Why Study Viruses?

Some Viruses are Useful

Sources of Enzymes

RNA polymerase (T7 phage)

Genetic Pesticides

gene from baculovirus against worms



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



Gene Vector for Protein Production

baculovirus, adenovirus

vaccine component

Gene Vector for Treatment of Genetic Diseases

retrovirus

immunodeficient cases Parungao-Balolong 2011-2012Friday, June 17, 2011

Why Study Viruses?Virus Studies Have Contributed to Knowledge

Hershey and Chase experiment (T2 phage)


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)


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)


Nature of VirusesViruses are Small Particles


Nature of VirusesViruses Have Genes

virus use host cell proteins

virus code efficiently

multifunctional


Nature of VirusesViruses are Parasites


Origin & Evolution of VirusesOrigin & Evolution of Viruses


Virology lecture 1 introduction

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