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23 Cards in this Set
- Front
- Back
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what influenza virus is most likely to cause you a problem?
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A
note there are: A, B, C viruses of humans, swine, horses, birds |
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influenza is what kind of virus?
What is important about its genome? *********** |
ORTHOMYXOVIRUSES
the genome has 8 single stranded SEGMENTS of RNA Each segment=1 gene if two influenza viruses get encapsulated, because the genome is segment, you get a mixing of the segments, making new strains of the virus! |
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what do orthomiyxoviruses (influenza) need for replication?
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nucleus required (even though it is an RNA genome)
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what is Hemagglutinin?
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the attachment protein for influenza
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what is the major target for antibody against influenza?
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Hemagglutinin (blocks attachment)
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what portion of the influenza virus undergoes antigenic variation? what is important about this?
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Hemagglutinin (the attachment site)
this allows for a new strain to pop up each season |
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other than Hemagglutinin, what is another major protein on the influenza virus? What is its job?
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neuraminidase
removes sialic (neuraminic) acid residues from glycoproteins (note this is the opposite of what hemagglutinin does...which seems counter-intuitive, but what this does, is releases the virus that is attached to a cell that doesn't allow for replication) |
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other than the Hemagglutinin protein, what else undergoes antigenic variation?
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Neuraminidase
note: target for current antivirals |
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What H and N variants of influenza are able to infect humans?
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H 1-3
N1-2 |
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H5N1 is what?
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Bird flu
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What is responsible for typing of influenza
viruses into groups A, B, and C? *** |
S-Ag
(soluble antigen, also called RNP, or ribonucleo- protein antigen, are structural proteins of core |
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what causes the symptoms of the flu?
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largely the result of inflammation, interferon induction, cytokine release (“cytokine storm”).
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what is a common "melting pot" for both avian and human flu...that can lead to hybrid human flu (pandemic)
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PIGS
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what generally causes fatality associated with primary influenza pneumonia?
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secondary bacterial pneumonia (accounts for most fatalities)
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what is a classic test for influenza?
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hemagglutination-inhibition tests
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What are the 2 things that lead to antigenic variation?
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Antigenic drift - small changes in hemagglutinin and/or
neuraminidase single antigenic determinants. Due to mutation. Antigenic shift - major change in most all antigenic determinants of hemagglutinin and/or neuraminidase. Intragenomic or intergenomic recombination (segment exchange, reassortment) between human and animal viruses. |
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What is antigenic drift?
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small changes in hemagglutinin and/or
neuraminidase single antigenic determinants. Due to mutation |
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what is antigenic shift?
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Antigenic shift - major change in most all antigenic determinants of
hemagglutinin and/or neuraminidase. Intragenomic or intergenomic recombination (segment exchange, reassortment) between human and animal viruses. [this is where the pig comes into play] |
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was Swine flu due to drift or shift?
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drift
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how is influenza spread?
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respiratory droplets (inhalation)
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What is an important mediator for the recovery from influenza?
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IgA of major importance in recovery; IgG and cell-
mediated play a role. Length of immunity only 2-4 years |
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Amantadine/Rimantidine are used for what?
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preventative treatment of Type A influenza
Interfere with uncoating (M2 matrix). Not effective against H1N1 (swine) |
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Zanamivir, Oseltamivir, and Peramivir are used for what?
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therapeutic treatment of influenza
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