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11 Cards in this Set
- Front
- Back
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How do T cells get to the site of infection? |
Chemokines are produced at the site of infection
Endothelium exposed to microbes displays ligands for adhesion molecules
Effector T cells express adhesion molecules and chemokine receptors |
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What is the difference of an integrin and selectin interaction |
Selectin is much more loose compared to integrins |
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What is the difference between naive and effector T cells |
Naive T cells have receptors that keep them in the lymph nodes as long as possible, where as T cells favor migration to sites of infection
Naive T cells recognize the APC or dendritic cell |
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How do T cells migrate to sites of infection? |
It is NOT antigen specific move similarly to polys and find the endothelial targets
ONLY effect T cells that recognize their specific antigent stay to perfrom effect functions
S1P is produced at the infection but acts in a gradient moving it to the main site. S1P downregulates its own receptor allowing the cell to "forget" the call |
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What are different effector functions of CD4 and CD8 cells |
CD4 secrete cytokines and act on macros and B cells |
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What are the Helper T lymphocytes |
actual killing is a function of innate immune cells
Several types of helper T cells Th1/2/17 each vary based on which type they act on` |
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Describe the Th1 response |
Th1 recognized microbial antigens expressed on MHC class II molecules on MACROPHAGES
Secretes CD40 ligand and IFN-y to activate macrophages
Macrophages destroy phagolysosomes and release IL-12 which converts naive to effector T cells |
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Describe the Th2 response |
THINK allergies
Stimulate the eosinophil-predominant immune response
Th2 cells also dampen down the Th1 triggered macrophage activation in an attempt to repair
has mediators that kill parasites, IL-4 triggers IgE and IL-5 stimulates eosinophils
a greater Th2 response means an overall weaker Th1 response pulling from the same original pool of T cells |
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Describe the Th17 response |
produce cytokines that recruit neutrophils and monocytes to the infection
important in eradication of extracellular bacterial and fungal infections
produce Il-17 and IL-21
defects in immunity are associated with increased susceptibility to candida infections
redudant with extracellular humoral immunity |
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What are the effector functions of CD8 cytotoxic T lymphocytes |
CTLs adhere tightly to target cells to form an immunologic synapse
Cytotoxic granule exocytosis
Perforin and granzyme |
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How have bacteria evolved to avoid T cell mediated defense |
inhibit phagolyosome
inhibit antigen presentation
produce inhibitory cytokines
inhibit receptor for t cells |
