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27 Cards in this Set
- Front
- Back
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What are the inductive sites vs effector sites? (2)
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1)Inductive: site where the lymph nodes are
2) Effector sites: sites where cells are induced to travel to |
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What are the inductive sites?
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1) NALT
2) BALT 3) GALT |
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What are the effector sites?
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epithelium or lamina propria anywhere exposed to outside environment (exp. from nasal mucosa to genitourinary tract)
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What are the inductive sites in the NALT?
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1) tonsils
2) adenoids |
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What are the inductive sites in the GALT?
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1) PP
2) soliatary lymphoid nodules 3)appendix |
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What happens to a child who has had his tonsils taken out?
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poor immune response to polio vaccine
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Where are peyer's patches primarily located and what are they?
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aggregates of lymphoid follicles in terminal ileum
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What is the M cell and what does it do?
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specialized epithelium cell in Peyer's patch epithelium that take up antigen
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How can you differentiate an M cell from the rest of the Peyer's patch?
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The M cell has ruffles and thus creates a flattened area in the dome of the Peyer's patch
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Are M cells an APC?
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NOOOOOO
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What are the two cells that are specialized with antigen uptake in mucosa?
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1) dendritic cells
2) M cells |
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What cell types of the immune system are in the epithelium vs lamina propria of effector sites?
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epithelium: IELs (CD8-cytotoxic)
LP: activated cells of the other types |
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What is special about the IELs?
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-limited V regions/limited specificities
-can be of two types (CD8 α&alpha AND CD8αβ) |
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What is the pathways of how you get lymphocyte from inductive site to effector site? What is this process called?
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HOMING PROCESS
1) peyers patch activation 2) go to lymph node 3) go to heart 4) go back to LP to where you are needed |
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How do cytokines and CAMs direct homing?
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1) integrins on T cell, Α4Β7 interact with
2) Addressin MadCAM on endothelial cell 3) diapedese 4) chemokine receptor, CCR9 receptor on T cell is attracted to 5) chemokine CCL25 on epithelial cells |
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What provides epithelial cells on mucosal surfaces with an active barrier?
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1) bacteria bind via TLR or NODs (similar to TLR)
2) activation of receptor activates NFκB 3)NFκB turns on promoter for proinflammatory cytokines |
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What is the hallmark of effective immunization against enteric pathogens?
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IgA
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What are the 4 functions of IgA response?
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1) eliminate toxins in LP
2) neutralize pathogens in lumen 3) interact with M cells to Xport pathogen into lymphoid tissue 4) neutralize pathogens/toxins in epithelial and M cell vesicles |
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What is the difference between IgA1 vs IgA2?
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IgA2 is more resistant to proteases so the ratio of IgA1 to IgA2 ↓ as you progress down the gut epithelium
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What are the functions of IELs?
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kill infected epithelial cell
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Do IELs undergo thymic selection?
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no
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What happens during innate immunity?
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1) distressed cell secretes MICA and MICB
2) NKG2D cells bind MICA and MICB 3) NKG2D cells kill |
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What is oral tolerance?
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exposure to non living, non replicated antigens in the gut leads to local and systemic non-responsiveness
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How do commensal bacteria avoid the immune response?
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-secrete cytokines that prevent dendritic cell maturation
-immature dendritic cell sends weak signal to CD4 T cells so they become TH3 or Treg cells |
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What are the cytokines that the commensal bacteria secrete?
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TGF-Β
PGE<sub>2</sub> TSLP |
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Do activated T cells predominate in the mucosal immune system even when there is no infection
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yes
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What regulates the mucosal immune system?
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inhibitory macrophages
tolerance-inducing dendritic cells |
