respiratory viruses Flashcards
what is the virus family, genome, and virion of influenza virus
family - orthomyxovirus
genome - segmented (-) ssRNA
virion - enveloped
what strain of the influenza virus most commonly is associated with humans
type A influenza
what does HA stand for, what virus has these, and what is its function
Hemagglutin protein in infulenza viruses
-used for cell attachment/entry
what does NA stand for, what virus has this, and what is its function
- Neuroamidas protein in the infuenza virus
- used for budding/release
what strain of influenza is known to have an animal resovoir
type A (waterfowl)
where does replication occur for Type A influenza ?
in the host nucleus (unique b/c most RNA virus replicate in the host cytoplasm)
-Type a genome is (-) ssRNA
What other viruses with are unique to the rule in that they hava a (-)ssRNA genome but replicate in the nucleus
HTLV-1 virus
HIV
how is Type A influenza transmitted and what is its incubation time
aersol droplets (fairly contagious) -1 to 4 days incubation
what are the current circulating strains of seasonal influenza
H3N2, H1N1
Type A influenza can be prevented by administering a live attenuated vaccine, however this vaccine must be redeveloped each year, why ?
Antigenic shift, meaning the virus has rapidly changing proteins that can adapt evolve to become resistant
the live attenuated vaccine given to prevent influenza usually contains what strains ?
H3N2, H1N1, Type B strain
what influenza protein do antivirals amantidine and rimantidine block
Blocks M2 protein
-thus blocks nucleocapsid release/entry
what influenza protein does antiviral Tamiflu block
blocks NA (neuroamidase protein) -thus blocking budding/release
what was the most deathly influenza pandemic recorded, and what type of strain was it ?
1918 Spanish Flu
H1N1 virus causing cytokine storm (caused deaths)
It is believed that influenza pandemics arise from ?
avian strains of influenza
what avian influenza strains are known as Highly Pathogenic Avian Influenza
H5 and H7 strains
What is the family, genome, and virion of adenovirus
family - adenoviridae
genome - dsDNA
virion - nonenveloped
Gene expression for adenovirus occurs in 3 stages, what are they ?
1 - intermediate-early : E1A
2- early : E1B and more
3 - late
Genome replication in adenovirus is unique in that in order to copy both ends of the genome, the displaced strand must ______ to allow template copies to be made
circularize
-remember its dsDNA
what protein of the adenovirus works in the intermediate-early stage of gene expression to inactivate pRB (which allows for replication to occur)
E1A
what protein of the adenovirus works in the early stage of gene expression to inactivate p53 (which allows for replication to occur )
E1B
the adenovirus has specific proteins that block _____ induced apoptosis, and the action of _______ which work in translation
- TNF (tumor necrosis factor)
- IFN alpha and IFN beta
The symptoms of what 2 virus are the same as the common cold ?
Adenovirus and Rhinovirus
why is the adenovirus frequently used for gene therapy
b/c it has a segmented genome which diff. proteins can be added to
