Virology Introduction to the viruses Edward Jenner n

Virology Introduction to the viruses

Edward Jenner n n Vaccinations Cowpox ¨ cross protection against small pox n Variola virus ¨ ¨ n n Major § Blisters § Blindness § Death Minor Poxviridae ds. DNA

Viruses n n Define Classification ¨ Group n ¨ Family n ¨ -viridae Genus n ¨ NA -virus Species n Name

Host Affinity n Specific ¨ Host ¨ Cell n n type General Examples ¨ Bacteriophage ¨ Viroid (plant)

Host Range: Plants

Host Range: Bacteria

Host Range: Animals

Animal Virus Examples

Viral Culture n Culture ¨ Bacteria ¨ Chick Embryos ¨ Cell/Tissue n n Purified Assays ¨ Hemagglutination ¨ Plaque

Viral Characteristics n n n Acellular Infectious Phases Extracellular ¨ Intracellular ¨ n Viron structure ¨ Nucelocapsid n n ¨ Capsid NA +/- Envelope

Viral Morphology n Size ¨ 10 -400 n nm Structural components ¨ Nucleocapsid ¨ Envelope n (+/-) Classifications ¨ NA ¨ ss or ds

Size

Viral Capsid n Function ¨ Protect NA ¨ Aids in transfer to host n Structure ¨ Protein coat ¨ Capsomere arrange n n n Helical Polyhedral Complex

Polyhedral Capsids

Capsomeres are capsid subunits

Naked vs. Enveloped Viruses

Viral Envelope n n n 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

Envelope Glycoprotein Spikes

Viral NA n n DNA OR RNA Shape Circular ¨ Linear ¨ n Number One ¨ Or more ¨ n Strands ss ¨ ds ¨ + or - if RNA ¨

Viral Classification n n n ds. DNA ¨ Small pox ¨ Herpes ¨ Papilloma ss. DNA ¨ Parvo ds. RNA ¨ Rotavirus +ss. RNA ¨ Polio ¨ Rhino ¨ Corona -ss. RNA ¨ Measles, mumps ¨ Rabies ¨ Influenza Retroviruses ¨ HIV

Bacteriophage Life Cycle n Lytic ¨ ¨ n Attach and entry Synthesis Assembly Lysis Lysogenic ¨ ¨ Attach and entry NA in chromosome Binary fission Renters lytic phase n n n Synthesis Assembly Lysis

Lytic

Bacteriophage Lytic Cycle animation

Lysogenic

Specialized Transduction

Bacteriophage Cycle

Phage Cycle Summary

Viral Replication Differences

Viral Infections

Replication of Animal Viruses n n Attach Entry ¨ Direct Penetration ¨ Membrane fusion ¨ Endocytosis n n Uncoating Synthesis Assembly Release

Viral Attachment

Direct

Endocytosis vs. Membrane Fusion

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

NA synthesis n n n ds. DNA: usual replication (for most) ss. DNA ¨ complementary strand ¨ Normal replication ds. RNA ¨ + strand = m. RNA ¨ Template and copy +ss. RNA ¨ + strand = m. RNA ¨ Complimentary strand for template -ss. RNA ¨ Viral enzymes make + strand ¨ Template for m. RNA and -ss Retroviruses ¨ +ss. RNA (m. RNA to make DNA) ¨ Reverse transcriptase ¨ DNA is template for new +ss. RNA

DNA Virus Biosynthesis

RNA Virus

Retroviruses

Viral Assembly n DNA ¨ Nucleus ¨ Moves n to cytoplasm RNA ¨ cytoplasm

Use of ER and Golgi Herpes

Viral Release n Types ¨ Budding n n Acquire membranes envelope ¨ Exocytosis ¨ Lysis n Latency

Budding

Viral Exocytosis

Viral Lysis

Viral Damage

Viral Transmission

Acute vs. Latent

Viral Infections

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

Immune Response Adaptive Immunity

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

Prions n n Infectious proteins Structure Insoluble ¨ Beta pleated sheet ¨ n n Pr. Pc Pr. Psc Affects NS Fibrils ¨ Vacuoles (spongy) ¨ n Examples BSE ¨ CJD ¨ Scrapie ¨ Kuru ¨

Prion Production

Viral/Prion Related Diseases n n n n n ALZ MS Parkinsons ALS DM RA Hepatitis SLE Neoplasia

Other Proposed Viral Diseases

Questions?