Viruses and Computer Scientists

1. Viruses and Computer Scientists Courtney D. Corley Computational Epidemiology Research Laboratory Department of Computer Science University of North Texas Department of Biostatistics UNT Health Science Center

2. Motivation Why is a computer scientist looking at viruses?

3. Current Research in Comp Epi • Graph-based data mining (SUBDUE) • Dynamic social networks (STD transmission dynamics) • Models and tools to facilitate public health strategy evaluation • Global Stochastic Field Simulation • Agent-based Models

4. Herpes Simplex type-1

5. Herpes Simplex type-1

7. Smallpox

8. Smallpox

9. Overview • Motivation • Etymology • Epistemology • Living Cells • Virus definition • Viral diversity • Conclusion

10. Etymology • Derived from Latin: virulentuspoisonous • 1392 -- first used in English. • 1728 – “agent that causes infectious diseases” • 1972 – biological virus and metaphor for other parasitically reproducing things.

11. Virus A subcellular parasite with genes of DNA or RNA and which replicates inside the host cell upon which it relies for energy and protein synthesis. In addition, it has an extra-cellular form in which the virus genes are contained inside a protective coat

12. Epistemology part 1 Are viruses “GOOD” or “BAD”? • Biological Knowledgebase • Viro-therapy • Vectors • Nanotechnology – the golden thread

13. Epistemology part 2 Is a virus “ALIVE” or “DEAD” ?

14. Living Cells Which of the following apply to a living cell? • It contains genetic information (DNA) • It uses RNA as a genetic messenger • It is capable of making its own proteins • It generates its own energy • It is surrounded by a cell membrane

15. Living Cell

16. A Virus Flunks the “Living Cell” test • It is capable of making its own proteins • It generates its own energy Is the following true? • It is surrounded by a cell membrane

17. What defines a “VIRUS” • Cannot multiply without a host cell • Intracellular parasites • Two forms • Viron – inert particle that survives out of the host cell • Active intracellular phase • Capsid – Protein surrounding a length of nucleic acid (DNA or RNA) which caries the virus genes. • Viral Genome

18. Virus Lifecycle • Attachment to the correct host cell • Entry of the virus genome • Replication of the virus genome • Manufacture of the virus proteins • Assembly of new virus particles • Release of new virus particles from the host cell

19. Retrovirus: Infection and Replication

20. Thief Many animal viruses have anextra envelopeoutside the protein shell. This membrane isSTOLENfrom the previous host cell into which viruses have been stuck. Now, the virus encodedproteinsfunction todetect and bindto the next target cell

21. Animal Virus When an enveloped virus enters a new cell, its envelope layer merges with the cell membrane and the inner protein shell containing the nucleic acid enters. Once inside, the protein shell disassemblesexposing the genome

22. Bacterial Virus Cell wall protects cell membrane – so Bacteriophages do not bother with an outer envelope. Afterbinding to cell surface, they inject their genome into the bacterial cell and leave the protein shell behind

23. Summary • Viral Philosophy • Living Cells • Great Diversity • Animal • Bacteria

24. Thanks! References: “Molecular Biology Made Simple and Fun” Clark and Russell http://science.nhmccd.edu/biol/bio1int.htm#virus http://www.whfreeman.com/kuby/content/anm/kb03an01.htm http://www.hhmi.org/biointeractive/animations/anim_index.htm http://www.hhmi.org/biointeractive/animations/subunit/sub_frames.htm http://www.hhmi.org/biointeractive/animations/infection/inf_frames.htm http://pathmicro.med.sc.edu/weaver/testflash-1.htm http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter26/animations.html