Gut Immunology-1/27/16 Flashcards
In the development of oral tolerance, ags are captured in the lamina propria and peyers patches and carried to mesenteric LNs by these cells ____
DC’s
In the development of oral tolerance, DC’s stimulate expansion of induced Treg’s (iTregs) by a mechanism dependent on ___
TGF-b, RA, and IDO
In the development of oral tolerance, DC’s induce ___-secreting plasma cells through RA-dependent mechanisms in the mesenteric LN
IgA
In the development of oral tolerance, gut-homing iTregs are expanded in the lamina propria by ___-expressing macrophages
IL-10
The gut microbiota or its constituents can suppress allergic IR’s through the induction of ____
Tregs
___ cells suppress Th2 cells that are central to generating IgE and allergic effector cells
iTregs
Gut microbiota have what effect on the following regarding food tolerance? (Increase or decrease)
A) Tregs
B) B cells (IgE)
C) Basophils
A) Increase Tregs
B) Decrease IgE
C) Decrease basophils
An increase in Th__ cells are seen with food allergies
2
List nutritional factors that may promote food allergies:
List nutritional factors that may suppress food allergies/promote tolerance:
High fat diet and medium chain TGs
Vitamins A and D and long chain FA’s
What are the 2 non-toxic adverse food reactions?
Non-immune-mediated (food intolerance)
Immune-mediated (food allergy)
Non-immune-mediated (food intolerance) mechanisms include:
Pharmacological, enzymatic, certain irritants, and psycosomatic responses
Immune-mediated (food allergy) mechanisms include:
IgE-mediated (type 1 hypersensitivity)
Non-IgE-mediated: Type 3 hypersensitivity (IgG or IgM immune complex rxn) or Type 4 hypersensitivity (DTH or cell-mediated rxns)
An IgE-mediated response of food allergies is what type of hypersensitivity?
A non-IgE-mediated response of food allergies is what type of hypersensitivity?
Type 1
Type 4 (cellular mechanism) or type 3
When mast cells are activated by IgE, mast cells release these granules that lead to increase epithelial permeability:
Proteases –> tryptase (tight junction rearrangement)
Histamine
De novo synthesis of cytokines –> IL-1b, TNF-a
GI manifestations of food allergy are dependent on Th2 cytokines, including these cytokines____
IL-4,IL-13, IL-9
____ cells are central to both local and systemic manifestations of food allergy
Mast
___ and __ mediate the local acute GI response (diarrhea) to allergen exposure
PAF
Serotonin
Anaphylaxis is a rxn resulting from sudden release of multiple chemical mediators, as a result of events mediated by ___ abs.
IgE
What receptor on mast cells will bind IgE?
FcERI
Nut allergies are mediated by these Ab-Ab receptor combinations
IgE/FcERI
IgG1/FcyRII/III
___ released from activated mast cells act on C3 and C5 to locally generate C3a and C5a which activate mast cells to further exacerbate symptoms in anaphylaxis
Tryptase
What molecules/genes are the main predisposing factors for celiac disease?
HLA-DQ2 and DQ8
Serum Abs against the ubiquitous enzyme ___ are specifically associated with Celiac disease
Tissue Transglutaminase 2 (TG2)
Gluten is a ___-rich protein that is poorly digested in SI tract due to a lack of prolylendopeptidases. It is also rich in glutamine residues
Proline
