Starter Questions:

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• Starter Questions
• What did you think of this paper? Did you find
  it interesting? Is it important?
• What tissues does influenza infect? What immune
  mechanisms are important
• at this site of infection?
• This group hypothesized that increased innate
  immune responses might harm the
• host and help the pathogen (influenza).
• Did this hypothesis surprise you? Why or why
  not?

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Background

• 1918 influenza extremely pathogenic, killing 50
  million people world wide.
• H1N1 subtypebut other H1N1 subtypes are not so
  deadly
• Previously shown that infection with virus
  containing the 1918 H1 and N1 resulted in massive
  macrophage and neutrophil infiltrationthe cause
  of increased pathogenicity?

What do you guys think of this hypothesis?
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• Hemagglutinin receptor required for viral entry,
  binds to sialic acid reisdues on host cells.
• Neuraminidase aids in viral release from host
  cells by cleaving sialic residues from surface of
  host cells.

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Influenza infectious cycle
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Influenza strains used
Why did they decide to use the Tx/91 and
1918HA/NATx/91 viruses for this paper?
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Fig. 1
Lung titers
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Fig. 2
TX/91
1918 HA/NATX/91
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Fig. 3
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Fig. 4
Lung titers
Brain titers
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Fig. 5
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?1918 influenza increases certain innate immune
inflammatory responses and decreases type-I
Interferon responses in infected monkeys.
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