7. Gut Immunology Flashcards
How do isolated lymphoid follicles mature?
Intestinal epithelial cells and dendritic cells present to cryptopatches, causing them to develop into isolated lymphoid follicles.
What is an isolated lymphoid follicle?
A single B cell follicle that acts as an inductive site for IgA production
What does exposure to microbiota do to assist the intestine in its development?
Stimulates the proliferation of intestinal epithelial cells encrypts, resulting in their increased depth.
In the small intestine, increases the density of Paneth cells.
How do activated T and B cells in the mesenteric lymph node arrive in the lamina propria / mucosa?
They enter the mesenteric lymph node, enter the bloodstream through the thoracic duct, travel throughout the entire bloodstream, and then home in and enter the lamina propria / mucosa.
Which T cells would interact with an APC carrying an MAMP if the result was Crohn’s disease?
What would their product be?
Th1 / Th-17
Interferon gamma, TNF, IL-17
What T cells would interact with an APC carrying an MAMP if the result was homeostasis?
What would the products be?
T reg cells
IL-10 and TGF-beta
What T cells would interact with an APC carrying an MAMP if the result was allergy?
What would the products be?
Th2
IL-4, IL-5, IL-13
How do undigested dietary carbohydrates, in the presence of commensal bacteria, decrease host response to the same commensal bacteria?
Undigested dietary carbohydrates can be fermented into acetate.
Acetate can increase the presentation of IL-10 + T regs.
T regs decrease host response to commensal bacteria.
What are the functions of short-chain fatty acids (like acetate) produced by commensal bacteria on the G.I.?
Increased T reg presentation.
Increased IgA effectiveness.
Increased production of mucus.
What three things are all of critical importance to the formation of induced Tregs for use in the guts to inhibit inflammatory responses?
TGF-beta.
Retinoic acid.
An enzyme called “IDO.”
Which type of hypersensitivity is involved in IgE mediated reactions?
Which type of hypersensitivity is involved in IgG or IgM immune complexes?
Type I hypersensitivity.
Type III hypersensitivity.
What mediates non-IgE mediated adverse food reactions?
T cells
Are T cell mediated adverse food reactions immediate onset or delayed in onset?
T cell mediated adverse food reactions are delayed in onset.
If someone has an immediate allergic reaction to food, what is probably mediating that reaction?
IgE
In terms of a food intolerance, what is considered “late phase / delayed in onset?”
4 to 28 hours after ingestion.