Lecture 16 10/19/23

Question 1

What are the general characteristics of type 1 hypersensitivity?

Answer 1

-allergic reaction
-exaggerated/excessive immune response to harmless substance
-rapid onset

Question 2

What is type 1 hypersensitivity mediated by?

Answer 2

-IgE
-mast cells
-eosinophils
-basophils

Question 3

What is the main feature of asthma?

Answer 3

inflamed bronchial tubes

Question 4

Which epithelium-derived cytokines are involved in type 1 hypersensitivity?

Answer 4

-IL-25
-TSLP

Question 5

What is activated by IL-25 and TSLP?

Answer 5

-ILC2
-dendritic cells

Question 6

What is the pathway of activation in type 1 hypersensitivity?

Answer 6

-DCs phagocytose allergen
-DCs activate Th2 response; IL-4, IL-5, and IL-13 produced
-B cell differentiation induced
-plasma cells secrete IgE
-IgE sensitizes mast cells

Question 7

Which receptor does IgE bind to on the mast cell?

Answer 7

Fc-Epsilon

Question 8

What happens after the mast cell is exposed to allergen?

Answer 8

-immediate release of histamine
-intermediate release of leukotrienes and prostaglandins
-later secretion of IL-4, IL-5, and IL-13

Question 9

What is caused by histamine, leukotrienes, and prostaglandins?

Answer 9

-vasodilation
-vascular leaking
-bronchial constriction

Question 10

Which cytokine recruits eosinophils?

Answer 10

IL-5

Question 11

What do eosinophils do?

Answer 11

release toxic granules that contribute to inflammation/damage

Question 12

What are the characteristics of anaphylaxis?

Answer 12

-most extreme form of immediate hypersensitivity
-often lethal without prompt treatment

Question 13

What type of reactions can occur with food allergies?

Answer 13

-mild: irritation and irregularity in feces
-severe: vomiting, cramps, diarrhea (can be hemorrhagic)

Question 14

What are the characteristics of an intradermal skin test?

Answer 14

-small volume of dilute allergen injected intradermally
-local reaction characterized by redness and swelling indicates allergy

Question 15

What are the treatment options for allergies?

Answer 15

-avoid exposure
-topical/oral corticosteroids
-atopica
-apoquel
-allergen-specific immunotherapy

Question 16

What is atopica?

Answer 16

immunosuppressive drug that inhibits T cell function by depressing interleukin 2 production

Question 17

What is apoquel?

Answer 17

drug that targets pruritus and inflammation by interfering with Janus kinase pathway

Question 18

What are the characteristics of allergen immunotherapy?

Answer 18

-administration of gradually increasing doses of specific allergen over long period of time
-goal is to reduce reaction and symptoms by desensitizing immune system

Question 19

How does allergen immunotherapy work, microscopically?

Answer 19

-injections promote IgG production instead of IgE, leading to less recruitment of mast cells and eosinophils
-DC function is restored, inducing Tregs