Module 7: Type I

Question 1

3 steps in allergic response

Answer 1

Allergen enters the body and causes Ab production (IgE, cytotropic Ab)

IgE binds to basophil or mast cells through CH4 domain

Upon second exposure, IgE surface Ab are cross linked, leading to degranulation of basophil/mast cells

Question 2

Activation of mast cells results in (3)

Answer 2

Secretion of granular contents
Synthesis and secretion of lipid mediators
Synthesis and secretion of cytokines

Question 3

Secretion of granular contents

Answer 3

Granules contain Histamine and Eosinophil chemotactic factor

Question 4

Histamine causes

Answer 4

contraction of bronchioles, smooth muscle
Increase in capillary permeability
Increase is mucous gland secretions
Stimulation of nerve endings

Question 5

Eosinophil Chemotactic Factor of Anaphylaxis

Answer 5

attracts eosinophils to the site

Question 6

Eosinophil function (2)

Answer 6

phagocytosis

Release of histamine and phospholipase D (downplays effect of histamine)

Question 7

Synthesis and secretion of lipid mediators

Answer 7

Mast cells and basophils produce New Lipid Mediators of inflammation

• Prostaglandins cause vasodilation and increased vasc. permeability
• Leudotrienes cause increased vasc. permeability, bronchoconstriction, mucous secretions

Question 8

Synthesis and secretion of cytokines

Answer 8

cytokines produced by mast cells (late phase reaction, 6-24hr post exposure)

Question 9

Cytokines produced by mast cells (4)

Answer 9

Tumor necrosis factor and IL4: promote neutrophil/eosinophil rich inflammation

IL3: promotes mast cell proliferation

IL5: eosinophil activator