Hypersensitivity Flashcards
How are hypersensitivity reactions defined?
By effector mechanisms
T/F Proteins or glycoproteins could be considered Allergens
True
Allergens have enzymatic activity and are often _______
proteases
Describe the presence of allergens at mucosal surfaces
Low, persistent concentrations at mucosal surfaces
Give two examples of potential inhaled allergens
- Plant pollen
2. Dust mite feces
Give two examples of injected allergens
- Insect venom
2. Drugs
Give two examples of ingested allergens
- Peanuts
2. Shellfish
List some general steps as to how someone would become allergic to pollen
- First exposure to pollen
- Extraction of antigen
- Activation of antigen-specific T cells
- Production of IgE and its binding to mast cells
What is the mechanism of a Type I hypersensitivity?
Allergen induces cross-linking of IgE bound to mast cells and basophils with release of vasoactive mediators
What are the typical manifestations of type I hypersensitivity?
Could include:
- Systemic anaphylaxis
- Localized anaphylaxis
Such as:
- Hay fever
- Asthma
- Hives
- Food allergies
- Eczema
What are the components of a typical adaptive immune response against helminth worms?
- T cells
- Cytokines
- Antibodies
- Effector cells
In a typical adaptive response to helminth worms, what are the T cells involved?
Th2 cells
In a typical adaptive response to helminth worms, what are the cytokines involved?
IL: 3, 4, 5 9, 10, 13
In a typical adaptive response to helminth worms, what are the antibodies involved?
IgE
IgG1
IgG4
In a typical adaptive response to helminth worms, what are effector cells involved?
Expanded populations of:
- Eosinophils
- Basophils
- Mast cells
What is the biological effect of the enzymes released by mast cells?
Remodel connective tissue matrix
Mast cell activation and degranulation affects what three major areas of teh body?
- GI tract
- Airways
- Blood vessels
How does Mast cell activation and degranulation affect the GI tract?
- Increased fluid secretion
- Increased peristalsis
These lead to the expulsion of GI contents by diarrhea and/or vomitin
How does Mast cell activation and degranulation affect the airways?
- Decreased diameter
- Increased mucus secretion
This leads to expulsion of airway contents through coughing, sneezing, and expulsion of phlegm
How does Mast cell activation and degranulation affect the Blood vessels?
- Increased blood flow
- Increased permeability
This leads to edema and inflammation, increased flow of antigens in lymph to lymph noodes
In mast cell activation and degranulation, which cytokines stimulate and amplify Th2 cell response?
IL 4 and 13
In mast cell activation and degranulation, which cytokines promote eosinophil production and activation?
IL: 3 and 5
GM-CSF
In mast cell activation and degranulation, what chemokine attractsmonocytes, macrophages, and neutrophils?
CCL3
What are the lipid mediators in Mast cells activation and degranulation?
- Leukotrienes: C4, D4, and E4
2. Platelet-activating factor
Which lipid mediator of mast cells:
- Cause smooth muscle contraction
- Increase vascular permeability
- Cause mucus secretion?
Leukotrienes C4, D4, E4
Which lipid mediator of mast cells:
- Attracts leukocytes
- Amplifies production of lipid mediators
- Activates neutrophils, eosinophils, and platelets?
Platelet-activating factor
T/F Major basic protein also poisons mammilian cells
true
What are the cytokines involved in eosinophil degranulation?
IL: 3.5
GM-CSF
For Eosinphil degranulation, what amplifies eosinophil production by bone marrow and causes eosinophil activation?
IL 3, 5
GM-CSF
What chemokine promotes influx of leukocytes in eosinophil activation and degranulation?
CXCL8
T/F the Lipid mediators for eosinophil activation and degranulation are the same as for mast cells
true
