Lecture 19 Flashcards
(13 cards)
How are gluten proteins broken down?
gliadin peptide does not break down easily, peptides rich in prolines/glutamines difficult to cleave
transglutaminase converse glutamine to glutamate
Why are celiac disease people like that
allergic to gliadin
what is an allergen?
environmental antigen that primes Th2 cells and drives IgE response
What causes an allergic reaction?
individual sensitized to innocuous antigen by producing IgE, subsequent exposure triggers immune response
What is atopy?
genetic predisposition to develop allergic (IgE-mediated) reaction
What are the steps of allergen sensitization?
- breach of the barrier
- exposure to allergen (initially asymptomatic)
- development of IgE antibody to allergen
What alarmins are released by epithelial cells upon exposure to allergen?
IL-25, Il-33, and TSPL (thymic stromal lymphopoietin)
What happens in subsequent exposure to an allergen?
Allergen re-exposed upon breach of barrier, mast cell degranulation promotes rapid Type II immune response
Why is allergy IgE mediated?
hypersensitivity and rapid expulsion
What is the goal of mast cell activation? How does this manifest?
rapid removal of allergen
GI: expulsion of contents
mucosal pathways: congestion, blockage of airways, swelling, itching, sneezing
blood vessels: increased fluid in tissues, increased flow of lymph nodes, hypotension –> anaphylaxis
How do activated mast cells drive allergic responses?
histamine, sensory neuronal cells (itching), vascular endothelium (increase blood flow, vessel permeability)
What do leukotrienes and prostaglandins do in the lungs? in GI tract? to other immune cells?
lungs: smooth muscle contraction, mucus secretion, bronchoconstriction, coughing
GI: vomiting and diarrhea
immune cells: chemotaxis of eosinophils & basophils (release proteases), Th2 cells (amplify)
What are medications to treat allergies?
anti-histamines, steroids, epinephrine
