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18 Cards in this Set
- Front
- Back
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* What is the structure of Retroviruses?
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enveloped, icosahedral
*2 copies of (+)RNA --> only truly diploid virus |
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Do retroviruses carry RNA-dependent RNA polymerase?
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No. RNA-dependent DNA polymerase (reverse transcriptase)
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** What is the DNA intermediate in retrovirus replication?
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provirus (just prior to insertion (Integrase) into host DNA)
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** What three genes do all retroviruses carry? what do they code for?
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GAg --> Group specific Antigens: internal proteins: capsid, matrix
Pol --> Enzymes: Reverse Transcriptase, etc. Env --> Envelope glycoproteins |
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How are morphologic distinctions made among retroviruses? what type is HIV? HTLV?
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capsid shape
HIV = D HTLV = C |
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* What are the two subtypes of human retroviruses?
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Oncovirinae: HTLV
Lentivirinae: HIV |
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What are the non-coding sequences at the end of retroviral genomes that are necessary for integration into host DNA?
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Long-terminal repeats (LTR)`
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What are the virulence enhancing "features" of retroviruses? which type have these?
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accessory genes --> increase virulence
more complex (HTLV) |
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* Which retroviral protein modulates attachment (to what on the host)? which modulates fusion?
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gp120 --> binds CD4
gp41 (fusion) |
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* What is the stage in replication when the retroviral DNA is ready to be included in the host DNA? --> what is produced from this?
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DNA provirus (which is inserted into normal host DNA (Integrase))
New viral RNA (used to make viral proteins and more RNA virus --> budding off) |
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Which of these are host enzymes? viral?
Reverse Transcriptase Integrase RNA polymerase |
Reverse Transcriptase (virus)
Integrase (virus) RNA polymerase (host) |
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Which retroviruses are associated with the development of leukemias, sarcomas, and lymphomas? what is the example?
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Oncoviruses
HTLV-1&2 |
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What are the two types of Oncoviruses? what type is HTLV?
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Direct/Acute (fast)
Indirect/Transactivating (promote uncontrolled cell growth) -- HTLV-1&2 |
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What do oncogenes encode?
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Proteins that are involved in growth control and differentiation
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What is Human T-lymphotropic virus (HTLV)? How is it transmitted?
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Transactivating leukemia virus
*Long latency period cell to cell contact during exchange of bodily fluids |
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What is the transcriptional regulator of HTLV? What does it infect (cells)? What disorder is it associated with?
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tax
CD4 Helper Ts neurologic |
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* What virus infects T cells, giving them a "Flower Cell" histologic appearance
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HTLV-1
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* What subtype of retrovirus contains HIV?
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Lentivirinae
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