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12 Cards in this Set
- Front
- Back
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Influenza virus
enveloped virus- outer layer is a lipid membrane taken from host cell in which the virus multiplies. |
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HA (Hemaglglutinin) and NA( Neuraminidase)
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Inserted into the lipid membrane are ‘spikes’, which are proteins – actually glycoproteins, because they consist of protein linked to sugars – known as HA (hemagglutinin; binds to cellular recpeptor- sialic acid) and NA (neuraminidase).
important in immune response; antibodies (proteins made by us to combat infection) against these spikes may protect against infection. The NA protein is the target of the antiviral drugs Relenza and Tamiflu. |
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M2 Protein
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Also embedded in the lipid membrane is the M2 protein, which is the target of the antiviral adamantanes – amantadine and rimantadine.
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M1 (Matrix) Protein
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Beneath the lipid membrane is a viral protein called M1, or matrix protein. This protein, which forms a shell, gives strength and rigidity to the lipid envelope.
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PB1, PB2, PA, NP
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Within the interior of the virion are the viral RNAs – 8 of them for influenza A viruses. These are the genetic material of the virus; they code for one or two proteins. Each RNA segment, as they are called, consists of RNA joined with several proteins shown in the diagram: B1, PB2, PA, NP( nucleocapsid protein; stabalizes RNA). These RNA segments are the genes of influenza virus.
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NEP
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interior of the virion also contains another protein called NEP. Nuclear export protein, replicates in nucleus.
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Where and who does it infect?
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can infect H20 and aquatic creatures- pratically every animal is susceptible which is why it spreads so easily. It also lives on inanimate objects.
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IAV Replication
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IAV
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Three types: A, B, C
• Hemagglutinin –16 –Sialic acid • α2,6-human • α2,3-bird • Neuraminidase –9 |
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Antigenic Drift/Shift
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IAV Complications
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• Primary viral pneumonia
• Secondary bacterial pneumonia • Reye syndrome – brain swelling; liver degeneration –Aspirin = disease co-factor |
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Influenza Vaccine
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• Live-attenuated – “flu mist”
• Inactivated –Formaldehyde-treated –IM injection –60-90% efficacy –Annual |
