8. Variola (smallpox) Flashcards
(14 cards)
What are the 2 poxviruses of the Chordopoxvirinae subfamily that ONLY infects humans?
Variola virus, molluscum contagiosum virus
Amount of deaths caused by smallpox during the 20th century?
300-500 million
How is smallpox contracted?
Inhalation
What is temporal regulation of transcription?
Process by which specific genes are transcribed at different times, as they are needed
Upon variola infection, what protein is needed right away? Why?
DNA-dependent RNA polymerase
To make mRNA
3 agents/methods that provided protection from smallpox?
- Inoculation w/ cowpox
- Variolation w/ dead viruses from scabs
- Inoculation w/ vaccinia virus
Why does variola package its RNA pol but not its DNA pol?
RNA pol is needed immediately to transcribe mRNA from the (-)RNA genome to translate early proteins
Viral DNA pol is one of the early proteins
Variola genome?
Linear dsDNA, ends sealed by hairpin loops (AT-rich)
Variola - site of genome replication?
Cytoplasm
How is variola spread in the body?
Blood/lymph
How is the variola genome protected from host exonucleases?
No free ends since hairpin loops are presented
Poxvirus genome replication requires intermediate-gene-specific viral factors and a host factor ______ exported from the nucleus
Vitf2
First step in poxvirus replication cycle?
Extracellular enveloped virus (EEV) binds via virion proteins and by glycosaminoglycans (GAGs) on target cell surface
3 reasons to study poxviruses even though variola has been eradicated?
- Bioterrorism threat
- Need for better vaccines
- Monkeypox threat