Hypersensitivity I, II - Grayson Flashcards
Allergic individuals exhibit the condition termed ___ and are termed ___. These individuals exhibit higher than normal levels of circulating ___ and ___—important effectors of the allergic response. ___ is linked to several genetic loci including region encoding several cytokine genes and HLA class ___ alleles.
Allergic individuals exhibit the condition termed atopy and are termed atopic. These individuals exhibit higher than normal levels of circulating IgE and eosinophils—important effectors of the allergic response. Atopy is linked to several genetic loci including regions encoding several cytokine genes and HLA class II alleles. Atopic: is a syndrome characterized by a tendency to be “hyperallergic”
___ in immune system genes can determine whether you are atopic or not.
Polymorphisms
___ allergen doses favor what response?
Low allergen doses favor Th2 response.
Low doses of antigens favor ___ response. The antigens are almost always very small and typically soluble. Allergens are always ___ because they are recognized by __ cells.
Low doses of antigens favor Th2 response. The antigens are almost always very small and typically soluble. Allergens are always peptides because they are recognized by Th2 cells.
Features of inhaled allergens that may promote the priming of Th2 cells that drive IgE response.
Protein - only proteins induce the ___ response
Allergens are often ____
A low dose of allergen favors ___ (cytokine) producing CD_ T__ cells
Allergen can diffuse out of particle into mucus because they are ___
Features of inhaled allergens that may promote the priming of Th2 cells that drive IgE response.
Protein - only proteins induce the T cell response
Allergens are often proteases
A low dose of allergen favors IL-4 (cytokine) producing CD4 Th2 cells
Allergen can diffuse out of particle into mucus because they are small
Cross linking antigen to IgE bound to mast cell induces what?
Mast cell activation and granule response
Granule release from mast cells in the GI tract will cause what?
Increased fluid secretion, increased peristalsis –> vomiting and diarrhea
Mast cell activation and granule release in the airways cause:
decreased diameter, increased mucus secretion –> congestion and blockage of airways (wheezing, coughing, phlegm)
Mast-cell activation and granule release in blood vessels cause:
increased blood flor, increased permeability –> increased fluid in tissues causing increased flow of lymph to lymph nodes, increased cells and protein in tissue, and an increased effector response in tissues
Mediators released by mast cells:
Enzymes are ____ and ___. They work by ___ the tissue matrix
Toxic mediators are __ and ___. These are toxic to ___, increase ___ permeability, and cause __ ___ contraction.
Cytokines are ___, ___, which stimulate Th2 response, and ___, __ and ___ which promote eosinophilic production and activation
Chemokines are ___ (MIP 1 alpha) which attract ___,__ and ___.
Lipid mediators are ___, which cause SM contraction, increased vascular permeability and stimulation of mucus secretion. ____ attracts leukocytes, amplified production of lipid mediators and activates __, __ and __.
Mediators released by mast cells:
Enzymes are tryptase and chymase. They work by remodeling the tissue matrix
Toxic mediators are heparin and histamine. These are toxic to parasites, increase vascular permeability, and cause smoth muscle contraction.
Cytokines are IL 4, IL-13, which stimulate Th2 response, and IL-3, IL-5, and GM-CSF which promote eosinophilic production and activation
Chemokines are CCL3 (MIP 1 alpha) which attract monocytes, neutrophils and macrophages.
Lipid mediators are leukotrienes, which cause SM contraction, increased vascular permeability and stimulation of mucus secretion. Platelet activating factor attracts leukocytes, amplified production of lipid mediators and activates neutriphils, eosinophils and platelets.
Type I HSR are usually done in two phases:Immediate and Late
Immediate and Late
Immediate Phase: in response to allergen binding and crosslinking of the IgE receptor, mast cells are rapidly triggered to release preformed granule-associated contents:
P____
L____
P___
H___
TNFa
Then, immediate phase initiates the production of:
Cytokines (IL-4, IL-5, IL-13, TNFa)
Chemokines
Leukotrienes
Results in the recruitment and activation of Th2 cells, eosinophils, basophils and neutrophils.
Late Phase occurs 8-12 hours later
Immediate and Late
Immediate Phase: in response to allergen binding and crosslinking of the IgE receptor, mast cells are rapidly triggered to release preformed granule-associated contents:
Prostaglandins
Leukotrienes
Platelet activating factor (PAF)
Histamine
TNFa
Then, immediate phase initiates the production of:
Cytokines (IL-4, IL-5, IL-13, TNFa)
Chemokines
Leukotrienes
Results in the recruitment and activation of Th2 cells, eosinophils, basophils and neutrophils.
Late Phase occurs 8-12 hours later
Which two cytokines are produced after allergy exposure?
IL4, and IL-13.
What are some possible reasons for why there is increased allergic airway disease?
- Antibiotic use early in life
- Altered gastrointestinal microbiota
- Dietary changes
____ are the mediators of peripheral immunologic tolerance
The normal microbiota may promote activation of _____ in the GI tract and thus prevent unwanted responses against many harmless antigens
How?
Most likely by releasing ___ signals that dampen inflammation and promote ___ activation
Regulatory T cells are the mediators of peripheral immunologic tolerance
The normal microbiota may promote activation of regulatory T cells in the GI tract and thus prevent unwanted responses against many harmless antigens
How?
Most likely by releasing chemical signals that dampen inflammation and promote regulatory T cell activation
Fox3p is expressed at high levels only in ____ cells.
CD4+CD25+T cells.
