DNA Virus 1 Flashcards
1
Q
key concepts of DNA viruses
A
- transcription and replication in nucleus (except pox)
- host RNA pol II transcribes mRNA (except pox)
- viral or hose DNA pol replicates genome
2
Q
parvovirus
A
-BK virus
3
Q
papova
A
warts
cancer
4
Q
adeno
A
colds
keratitis
5
Q
hepadna
A
hep B
6
Q
herpes
A
cold sores, etc
7
Q
pox
A
smallpox
8
Q
DNA genomes
A
- small circular DNA
- ejected various ways into the nucleus-see slide
9
Q
steps in DNA virus replication
A
- recognition
- attachment
- entry
- uncoating
- transcription of mRNA-Host RNA pol
- protein synthesis
- replication of the genome- host or viral DNA pol
- assembly of virions
- egress
10
Q
use of host RNA pol for mRNA transcription
A
- DNA viruses use the host RNA pol
- RNA pol II and TF (x,y) recognize viral promoters
- X and Y are proteins that enhance viral transcription
11
Q
TFs
A
- both cellular and viral factors regulate transcription by host RNA pol
- viral TFs are important virulence factors and are probably essential
- need cells to recognize viral TFs and promoters in order to transcribe them
12
Q
genome synthesis-host DNA pol
A
- some virus genomes are recognized by the host DNA pol complex
- these viruses do not encode their own polymerase-small genomes
- parvovirus-adeno associated virus 2
- need to be in dividing cells
13
Q
genome synthesis-viral DNA pol
A
- large DNA viruses encode their own pol and accessory proteins
- herpes, adeno
- don’t have to be in a replicating cell
14
Q
origins of diversity in DNA viruses
A
- recombination between and within genomes
- DNA pol have higher fidelity than RDRP
- mutations about 1/ 1 mil- like us
- genetically more stable than RNA viruses
15
Q
adenovirus diseases
A
- resp-bad cold/fever, pharyngoconjunctival fever, laryngitis and cough, pneumonia
- other sites-acute hemorrhagic cystitis, epidemic keratoconjunctivitis, gastroenteritis
16
Q
adeno epidemeology
A
- aerosol, fecal oral, objects
- poorly chlorinated pools
- children
- military recruits
- daycare centers, swimming clubs, boot camp
17
Q
adenovirus life cycle
A
- adeno fiber protein binds to cell receptor
- entry by endo
- endosome acidification causes fibers to lyse the vesicle
- capsid traffics to nucleus and DNA genome uncoats through nuclear pore
- genome replicates in nucleus
- host RNA pol II makes mRNA
- immediate early, early, late
- genome replication by viral DNA pol
- capsid assembly in nucleus
- virions egress by lysis
18
Q
gene expression phases in adeno
A
- immediate early for EIA
- helps make more mRNA
- early for DNA pol, which replicates genome
- late for structural proteins- for assembly
19
Q
adenovirus diagnosis and treatment
A
- match the diagnostic test to the patient sample
- culture, antigen detection, PCR, serology
- treat immunocompromised patients with cidofovir-dire cases and nephrotoxic
20
Q
adeno prevention
A
- vaccine
- used only for military personnel
- reinstated for use in late 2011
- incidence of Ad4 infections plummeted
21
Q
HPV diseases
A
- common
- epithelial disease-common, plantar, genital warts
- malignancies-head and neck cancer, cervical cancer, penile cancer
22
Q
HPV tissue tropism
A
- differentiated epithelial cells
- infects basal cells, limited amplification and maintenance replication until to top layer, then productive replication
23
Q
HPV infection
A
- cut
- productive life cycle for 2-3 weeks,grows up with skin
- growing cells express E7/E6, virus sheds
- lack of immune clearance
- skin becomes overgrown with HPV infected cells- oncogene activation
- causes invasive carcinoma
24
Q
HPV DNA replication
A
- host RNA pol transcribes viral mRNA
- host DNA pol synthesizes viral genomes
- viral factors E6 and E7 are oncogenes
25
HPV diagnosis and treatment
- diagnosis for genital HPV is recommended-DNA tests for type, important to screen for 13 high risk types linked to cancer
- treat warts by excision- freezing, chemical ablation, coposcopy
- treat malignancies with oncotherapy
26
HPV vaccine
- gardasil-quadrivalent for 6,11,16,18
- ceravix is 16,18
- both are virus like particles-empty capsids- makes antibodies to L proteins in genome
