Hypersensitivity Flashcards
What are the functions of IL-4
- induce differentiation of Th2 cells
- cause class switching to IgE
What receptor does IgE bind to on mast cells, basophils and activated eosinophils?
FceRI
How is IgE synthesized?
IgE is synthesized from class switching
IgE has how many constant domains
2
IgE does not play a role in
A. Complement fixation B. Opsonization C. Allergic Reactions D. Defense against parasitic worms E. A & B F C & D
E
When is IgE synthesized?
When Th2 cells secrete IL-4 which stimulates B cells to class switch and secrete IgE
How does the adaptive immune system play a role in parasitic infections
Th2 cells secrete IL-4 to induce the differentiation of more Th2 cells and class switching of B cells to make IgE
What happens to IgE once it is synthesized
it diffuses across vessel endothelium out of the blood to bind to mast cells
T/F: FceRII is a high affinity receptor for IgE
False
*FceRI
What chain of the FceRI receptor binds IgE
the alpha chain
The _____ chain of FceRI binds IgE
Alpha
Mast cells are located in all of the following locations except
A. Tissue Lining B. Vascularized Tissue C. Mucosal Tissue D. Blood E. Connective Tissue
D. Blood
*basophils are located in in the blood
Mast cells are ____ lived while basophils are ____ lived
Short, long
Mast cells in mucosal tissue express which protease
Tryptase
Mast cells in connective tissue express which protease?
ChymoTryptase
-
-
Which granulocyte is mainly present in blood?
Basophils
_______ on mast cells and basophils secrete cytokines that result in Th2 response and eosinophil activation
Toll Like receptors
Which cytokine is responsible for Eosinophil production and activation
IL-5
Eosinophils are mainly located
A. in blood
B. in tissue linings
C. in lymph
D. in connective tissues
D
What structures on basophils and mast cells recognize features of pathogens
Toll Like Receptors
What is the role of IL-5 in the development of immunity against parasites
eosinophil production and activation
List the type of preformed mast cell mediators (3)
- enzyme
- toxic mediator
- cytokine
What are the enzymatic preformed mediators of mast cells?
-tryptase and and chymotryptase
What do the mast cell enzymatic preformed mediators do?
remodel the ECM of tissue to dislodge parasite
What are the toxic preformed mediators of mast cells?
Histamine and Heparin and serotonin
What is the main effect of the release of histamine from mast cells?
-increased blood flow triggering inflammation
Where are H1 receptors for histamine located? What are the effects at each location?
-Vascular endothelial cells: vasodilation (increased permeability)
-Smooth Muscle cells: bronchoconstriction
Heart & Brain
H1 histamine receptors are located everywhere except
A. vascular endothelium B. GI tract C. Smooth Muscle D. Heart E. Brain
B.
*H2 receptors are in the GI and vascular endothelium
Where are H2 receptors located?
Vascular endothelium and GI
H3 and H4 receptors are located
in CNS and bone marrow
Which cytokine is a preformed mediator secreted by mast cells?
TNF-alpha
What does the preformed mediator TNF-alpha do (3)
- promotes inflammation
- stimulates cytokine production
- activates endothelium to express adhesion molecules
What is the importance of endothelial cell activation upon TNF-alpha
It causes the cells to express adhesion molecules allowing other immune cells to enter the tissue
What are the categories of newly synthesized mast cell mediators (3)
- cytokines
- chemokines
- lipid mediators
IL-4 and IL-13 from mast cells are _______ mediators
*chart on slide 13
Newly synthesized
What do newly synthesized mast cell mediators cause?
Sustained effects (late phase reaction)
Which category of mast cell mediators are responsible for the late phase reaction
newly synthesized
What chemokine plays a role in mast cel newly synthesized mediators?
CCL3
What does CCL3 do in mast cell mediation
Attracts monocytes, macrophages and neutrophils
What cytokine(s) promotes eosinophil production and activation
IL-5 & IL-3
What cytokines are a newly synthesized mast cell mediator the stimulates and amplifies the Th2 response
IL-4 and IL-13
What do prostaglandins do? (3)
- cause smooth muscle contraction
- increase vascular permeability
- cause mucus secretion
How are leukotrienes formed?
When arachidonic acid goes through the lipogenase pathway
Which pathway does arachidonic acid undergo to form prostaglandins?
Cyclooxygenase paths
T/F: Leukotrienes and Prostaglandins can be blocked by aspirin
False
*only Prostaglandins
Eosinophils are resident in
-connective tissue under respiratory GI and urogenital tracts
Which of the following cells types are exclusively involved in the late phase reaction
A. Basophils
B. Mast Cells
C. Eosinophils
C