RNA Viruses 2 Flashcards
Rotavirus general appearance
dsRNA
segmented
naked
icosohedron
Influenza virus general appearance
(-)ssRNA
segmented
enveloped
HIV virus general appearance
( + ) ssRNA
2 copies
enveloped
NO RDRP
Rotavirus clinical features
- Severe gastroenteritis (water diarrhea, dehydration)
- Mostly children adults are usually asymptomatic
- Vaccine
Rotavirus Life cycle
- Phagocytosis
- uncoated in endosome but keeps loose caspid for protection
- genome is segmented
- mRNA transcription –> translation
- Once proteins are translated new virions and genomes are synthesized (translation and replication)
- Virions assemble then bud into rough ER
- Egress via lysis or exocytosis
- virions mature in gut lumen
Influenza clinical features
Uncomplicated v. complicated
Acute respiratory illness
Uncomplicated = upper and/or lower resp. tract involvement; fever, headache, myalgia, and weakness
Complicated = 1 degree pneumonia then 2 degree bacterial pneumonia; muscle pain and breakdown
Treatment with antiviral drugs
Vaccine
Influenza Life Cycle
Endocytosis the release (-)ssRNA after uncoating
In nucleau: transcription and Replication by RDRP
Protein and genome accumulate at membrane, assemble, then leave by budding
release from sialic acid on cell surface
Stages of HIV disease
- Exposure (transmission)
- Primary HIV infection (acute phase)
- Serocinversion
- Latent period
- Early symptomatic HIV infection
- AIDS (CD4 lower than 200)
- Advanced HIV infection (CD4 below 50)
HIV cell tropism
- Only affects humans
- binds to CD4 and Chemokine proteins on T cells, and macrophages
- depletion of these cells and chronic immune activation causes immunodeficiency
HIV Life Cycle
- envelope protein binds to CD4 and Chemokine co-receptor
- fusion the uncoating then RT converts (+)ssRNA to dsDNA
- this dsDNS inserts itself into host genome where it stays for life
- normal host cell transcription to mRNA
- viral protein and genome bud from cell and mature outside of cell
- protease cleaves caspid to form final chape
