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Flashcards in Retroviruses Deck (7)
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Define the 3 activites of Reverse transcriptase in retroviral transcription.

1. RNA-dependent DNA synthesis (1st strand)
2. RNAse H (degradation of RNA in hybrid)
3. DNA-dependent DNA synthesis (2nd strand = dsDNA)


Describe the clinical significance of the high error rate in Reverse transcriptase.

Gives retroviruses high variability = the ability to outrun CTLs, ABs, harder to make vaccines.


What do integrase, reverse transcriptase and protease have in common?

These are encoded by pol gene (enzymatic activity) in pro-virus and are both targets for anti-viral therapy.


Describe how insertional mutagenesis of retroviral DNA can increase cancer risk.

HIV integration can turn on oncogenes or damage nearby cellular genes


How do ready-made HIV envelope glycoproteins escape host immune system?

Envelope proteins (trimer) is extensively glycosylated in secretory pathway to protect the virus from immune system.


Describe the spread, prevalence and diseases of: HTLV-1 infection.

Tsm: breast milk, cell-to-cell contact, male to female sex tsm;
Prevalence: Carribeans and Aborigines;
Diseases: chronic (autoimmune) inflammation, Adult T cell leukemia


Describe the spread, prevalence and diseases of: ATL infection

Tsm: breast milk;
Prevalence: Clustering in Kyushu Japan;
Diseases: T cell leukemia with HIGH WBC (<450,000!!)