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16 Cards in this Set
- Front
- Back
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* What is the main function of cell-mediated immunity?
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elimination of intracellular microbes
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What are the secondary (peripheral) lymphoid tissues (3)? what happens here?
what are the primary lymphoid organs? |
lymph nodes, spleen, MALT
naive T and B cells first encounter antigen bone marrow and thymus |
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* Which cytokine controls clonal expansion of T cells? where does it come from?
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IL-2
from within the T cell itself --> onto the IL-2Receptor (*triggered by CD28=B7 linkage) |
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What are the three effector T cells?
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Cytotoxic CD8
Th1 CD4 Th2 CD4 |
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What is meant by the term anergy?
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no response of T-cells to APC/antigen without CD28/B7 co-activation
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What is CD40?
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Another co-stimulator on APC that binds CD40L on Tcell (in addition to CD28/B7 co-stimulator)
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What surface molecule is produced by CD4 cells to activate macrophages and B cells?
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CD40
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Which CD4 cell primarily activates macrophages? which primarily functions in proliferation of naive B cells (inducing Ab production)?
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Th1 (macrophages)
Th2 (B cells) |
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General, what are the functions of helper T cells?
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expressing surface molecules (CD40) and cytokines that activate macrophages and B lymphocytes
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What is the main function of cell mediated immunity?
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eradicate microbes that survive within phagocytes or infect non-phagocytic cells (intracellular pathogens)
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Can activated T cells recognize antigen in tissue other than secondary lymphoid organs?
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Yes! this is their job. after activation they migrate to sites of infection
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After a T cell migrates to the peripheral tissue, what happens if it does not encounter the antigen it is specific for?
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returns to circulation
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*Is the Th1 or Th2 response more effective against intracellular pathogens? (the other will be better against extracellular)
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Th1 --> INF-y --> Macrophages --> Intracellular
Th2 --> B Cells --> Abs --> Extracellular |
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Which cell type contains lytic granules and cytotoxins?
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CD8
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What are the specific cytotoxins of CD8 cells and what are their roles?
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perforin: from membrane pores --> lysis
granzymes: induce apoptosis |
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What are some ways that Pathogens evade Cell mediated immunity?
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Prevent fusion of phagosome-lysosome
inhibit antigen presentation (several steps along way of antigen processing presentation pathway) Inhibition of macrophage activation Blocking of cytokines (when trying to activate other cells) |
