Mechanisms Of Host Defense - Bowden Flashcards
How are single toxins or epithelial Attachment of bacteria resolved? 5
Usually can be taken care of simply by binding with AB
What innate mechanisms disrupt and destroy EC Bacteria? 6
Epithelia barrier (w/ normal flora)
Alternative C’
Phagocytes: φ and neutrophils
Inflammatory cytokines/chemokines
How is Extracellular bacteria recognized by the innate immune system? 7
Via PAMPs and C’
How is Extracellular bacteria identified by the adaptive immune system? 8
CD4+ activation:
Ab production via B cells
Macrophage activation in the periphery
How is destruction of EC bacteria furthered by C’? 9
Binding of C’ exponentially increases phagocytosis
How do Abs of the Humoral immunity play a major role in resolving EC bacteria? 10
Blocks bacterial surface transport (no food)
Triggers C’ mediated damage
Blocks bacterial Attachment to host cell membrane
Blocks bacterial factors
Opsonizes
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What are some of the main ways in which EC bacteria & Fungi are able to evade phagocytosis? 12
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What are some common ways in which bacteria is able to evade complement? 14
Outer coat/capsule blocks C’
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How is Neisseria gonorrhoeae so good at evading phagocytosis? 15
Doesn’t evoke a large Ab response
Secretes IgA protease - destroys Abs
Release blebs that absorbs and destroys Abs
Alters its surface expression
What are the three ways N gonorrhoeae changes its antigenic composition? 15
Contains sialylated LPS (better resembles mammals)
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What cells resolve IC bacteria? 17
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What is the adaptive immune response to IC bacteria? 17
Activates phagocytes to eliminate the microbe
CD8 response
In terms of IC bacteria growth control what happens when IL-12 or IFN-γ is knocked out? 18
IL-12 knockout –> there is a REDUCED ability to control bacterial growth
IFNγ knockout –> there is NO ability to control bacterial growth
