12.11 Immunology: Normal microbiota 2 Flashcards
How are T and B cells activated?
Enter blood, acquire (a4B7 integrin which binds MAdCAM-1 on vascular endothelium of all mucosal surfaces) and ChK R’s.
Migrate to LP
Activated B cells–>IgA
CD4 T cells (mostly Treg)
CD8 T cells (against infection)
These distribute through all mucosal surfaces
What comprises intra-epithelial lymphocytes?
Many T cell types (incld. aB CD8)
Both ____ and ___ takes place in MALT
Both stimulation and supression takes place in MALT
What do the direct and indirect effects on the mucous layer and gut epithelium from microbiota refer to?
TLRs, PRRs, PAMPS
When do Peyer’s patches, mesenteric LNs and ILFs develop?
Peyers, mesenteric LNs: prenatally
ILFs: postnatally
What are germ free mice deficient in (3)?
IgA, lymphoid tissue, MAIT cells
What occurs with acquisition of intestinal microbiota?
What does this skew towards?
PAMP interactions
Th2 and Treg responses
How does the gut epithelium and lymphoid tissue discriminate between friend/foe?
PRR sense numbers
PRR detect invasion
Differential interaction with PRR
Microbial interactions determine gut immune response. What is the balance between?
Tolerance (physiological inflammation)
Th2, Treg, IL-22, IL-10
Immunity (pathological inflammation)
Th17, Th1, IL-1, IL-18
What happens in the Kwashiorkor twin after change to therapeutic diet?
Could not maintain change
What happened in germ free mice that were transplanted with the kwashiorkor microbiome?
They lost weight, change of microbiome composition
What did Kwashiorkor microbiota generate?
Products that selectively inhibited TCA cycle enzymes
What are high fat diets/obesity associated with?
Decrease in microbiotal diversity (insulin resistance, TGs, chol and insulin increase)
What is the microbiome like in type 2 diabetes?
Predictable
What occurs in obesity (with regards to inflammation)?
What is increased in lean subjects?
Inflammatory cytokines (TNFa, IL-1, IL-6, IL17), increase in mast, T cells and MPs
Increase in Tregs
