Immunology II (11.30.17)

Question 1

Define sensitization

Answer 1

first exposure to antigen with immune response (antibody)

Question 2

What is a type I hypersensitivity?

Answer 2

Allergy or anaphylaxis

Question 3

Which hypersensitivity reactions are antibody mediated?

Answer 3

Type I, II, III

Question 4

Which antibody is involved in Type I hypersensitivity?

Answer 4

IgE

Question 5

Where does IgE bind?

Answer 5

Mast cells

Question 6

What is the mechanism of type I hypersensitivity?

Answer 6

• First exposure causes IgE formation
• IgE binds to mast cells
• Antigen crosslinkes to 2 IgEs on surface of mast cell
• Degranulation
• Release of mediators

Question 7

What is the time frame for Type 1 hypersensitivity?

Answer 7

minutes

Question 8

Result of Type I hypersensitivity?

Answer 8

• increased vascular permeability
• Edema
• Smooth muscle contraction

Question 9

What are the symptoms/clinical manifestations associated with Type 1 hypersensitivity?

Answer 9

• Edema
• erythema
• itching
• urticaria
• eczema
• rhinitis
• conjunctivitis
• asthma

Question 10

During sensitization the APC picks up allergen and presents it to what type of cell?

Answer 10

T-helper 2 cell

Question 11

What does the T-helper 2 cell do in regards to allergic response?

Answer 11

Th 2 cell helps a B cell become a plasma cell

Question 12

What type of cell produces IgE?

Answer 12

plasma cells

Question 13

What are the effects of histamine?

Answer 13

• vasodilation
• increased capillary permeability
• smooth muscle contraction

Question 14

What is the effect of Slow-reacting substance of anaphylaxis (SRS-A) [leukotrienes]?

Answer 14

• increased vascular permeability

- smooth msucle contraction

Question 15

What is the effect of Eosinophil chemotactic factor of anaphylaxis (ECF-A)?

Answer 15

• release histaminase
• release arylsulfatase

*these degrade histamine and SRS-A

Question 16

What are the effect of prostaglandins and thromboxanes?

Answer 16

• Dilation and increased permeability of capillaries
• bronchoconstriction
• aggregate platelets

Question 17

What is the effect of platelet-activating factor (PAF)?

Answer 17

• Bronchoconstriction
• hypotension
• vascular permeability

Question 18

Which antibody is involved in Type II hypersensitivity reaction?

Answer 18

IgG

Question 19

Name the steps in Type II hypersensitivity

Answer 19

1. Antigen on the cell surface combine with IgG antibody

2. Complement-mediated lysis of the cells

Question 20

What is the typical time of onset or a Type II hypersensitivity reaction (cytotoxic)

Answer 20

hours to days

Question 21

Live attenuated vaccine

Answer 21

• weakened virus
• must be refrigerated
• not for immune compromised or pregnancy

Examples: measles, mumps, reubella, varicella, rotavirus, yellow fever

Question 22

Inactivated vaccine

Answer 22

• don’t require refrigeration
• induce weaker immune response
• need multiple doses to sustain immunity

Examples: poliovirus, hepatitis A, Japanese encephalititis

Question 23

Subunit vaccine

Answer 23

Use a component of the pathogen as vaccine to mimic exposure

-Weaker than live attenuated

Question 24

Conjugate subunit vaccine

Answer 24

Technology binds polysaccharide from bacterial capsule to a carrie protein.

This antigen combo induces long-term protection

Ex. Hib, Pneumococcal, meningococcal