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Flashcards in 10 Oral Tolerance Deck (16)
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mucosal immunity, in addition to providing defense at all mucosal surfaces does what

prevents Ag from entering circulation
prevents systemic immune response to an inappropriate Ag exposure


low dose of an oral Ag will result in

induciton of Th2 (IL-4 and -10) and TGFbeta secreting regulatory cells
leads to active suppression and immunologic hyporesponsiveness


high dose of an oral Ag will result in

deletion of anergy of Th1 and Th2 cells --> clonal anergy/depletion and
immunological hyporesponsiveness


stratification vs compartmentalization

stratification: minimizing contact between bacteria and epithelial layer by mucins, defensins, IgA
Compartmentalization: confining bacteria to intestinal sties and limiting exposure


describe immune exclusion

IgA traps Ag at mucosal surface where it is subject to degradation by defensins


intestinal epithelial cells play what important roleS in mucosal immunity

constant translocation of IgA (or IgM because J chain)
nonprofessional Ag presentation


in order to limit inflammation in GI tract, what receptor is moved and to where

TLRs are located on the basolateral side as opposed to apical side (only what gets past barrier induces inflammation)
NLRs (for intracellular stuff) remain


regardless of IgAs presence in the lamina propria of GI, what is produced and why

Secretory component that transports Ab across mucosal epithelial cell layer
ensures SC is not limited during an immune response


sits above peyer's patches, uptakes whole Ag and transports it into lumen for DC sampling

Microfold cells (M)


CD103+ cells

Specialized DCs in the GALT
can extend dendrites into lumen
produce Retinoic acid
produce anti-inflammatory cytokines: TGF-beta, IL-10 and IL-2


B cells in peyers patches primarily produce



IgA is important in maintaining homeostasis because

it does not fix complement, only neutralizes through binding - therefore clears immune complex without inflammation


gamma delta T cells are unique in what two ways

recognize lipid Ag (not just protein like their alpha:beta counterparts)
can be directly activated by DAMPs and PAMPs


why are most IgA deficiencies not diagnosed

IgM will still be secreted through epithelial layer in absence of IgA due to SC


IBD is caused by what deficiencies of the immune system

defective defensin - inadequate negative regulation
overactive Th17
granulamatous inflammation by Th1
defective Treg function


malnutrition is to immunosuppression/susceptibility to infection as overnutrition is to

immunoactivation - susceptibility to inflammatory disease