Retroviridae Flashcards
why retro?
retro - reverse transcription
Subfamilies
- Orthoretrovirinae
- Spimaretrovirinae
Ortoretrovirinae genera
Alpha-, Beta-, Gamma-, Delta-, Epsilonretrovirus and Lentivirus genus
Spumaretrovirinae genera
Bovi-, Equi-, Felispurmavirus genus
Morphology
diploid (only diploid virus), +ssRNA genome, helical + icosahedral capsid, enveloped, big
Resistance
very sensitive viruses (one of the most sensitive viruses)
Replication
Baltimore VI - viral reverse transcriptase -> integration, provirus
Type of infection
Cell-associated infection, because the cells protect the viruses from the environment
Genetic structure
characteristic, SHORT
5’-LTR-gag-pro-env-pol-LTR-3’
+/- onc, substitution mutant -> transforming, defective virus
what does onc gene sequence cause?
tumors
what sequence does “onc” usually replace?
env - the sequence for envelope
Oncogenic = ?
transforming viruses, need helpers for multiplication
multiplication competent viruses
Strong CPE, oncogenic as well
Transmission
transplacental (tolerance!), cell associated (germ cells, colostrum, epithel), arbo
Antigenic properties
- good antigens
- hypervariable surface antigens, Ig-s are not effectige against integrated viruses (->life long infection), destruction of the immune-system (destrow WBC - attack lymphatic tissue)