Chapter 6: T-cell-mediated immunity & effector mechanisms

Question 1

How was cell-mediated immunity discovered?

Answer 1

immunity transferred from one lab animal to a naïve animal only by cells (T-cells)

Question 2

Phagocyte with ingested microbes in vesicles leads to…

Answer 2

macrophage activation
inflammation
- via T cells

Question 3

Infected cell with microbes in cytoplasm leads to…

Answer 3

killing of infected cells via CD8+

Question 4

What are the target cells of Th1?

Answer 4

macrophages

Question 5

What are the target cells of Th2?

Answer 5

eosinophils
(B cells and macrophages)

Question 6

What are the target cells of Th17?

Answer 6

neutrophils

Question 7

What are the defenses for Th1?

Answer 7

intracellular pathogens

Question 8

What are the defenses for Th2?

Answer 8

parasites (helminths)

Question 9

What are the defenses for Th17?

Answer 9

extracellular pathogens

Question 10

What is the role in disease for Th1?

Answer 10

autoimmunity
chronic inflammation

Question 11

What is the role in disease for Th2?

Answer 11

allergy

Question 12

What is the role in disease for Th17?

Answer 12

autoimmunity

Question 13

What are the general properties of T cell cytokines?

Answer 13

• produced transiently in response to antigen
• acts on the same cell or nearby cells
• each cytokine has multiple biological actions
• redundancy

Question 14

What are the cytokines of selected T cell cytokines?

Answer 14

IL-2
interferon-y
IL-4
IL-5
IL-17
IL-22
TGF-B

Question 15

What is the signature cytokine of Th1 cell?

Answer 15

IFN-y

Question 16

What is the result of the Th1 cell activation?

Answer 16

classical macrophage activation
- increased expression of MHC and costimulators
- secretion of cytokines

Question 17

What allows for the Th1 cells to be formed?

Answer 17

• intracellular microbes plus either a dendrictic cell (IL-12) or NK cell (IFN-y)

Question 18

What allows for the Th2 cells to be formed?

Answer 18

• helminths plus mast cell and eosinophil (IL-4)

Question 19

What allows for the Th17 cells to be formed?

Answer 19

• extracellular, fungi, bacteria plus dendritic cell (IL-1, IL-6, IL-23, TGF-B)

Question 20

What are the signature cytokines of TH2 cells?

Answer 20

IL-4, IL-5, IL-13

Question 21

What does IL-5 from Th2 cells do?

Answer 21

eosinophil activation

Question 22

What does IL-4 alone from Th2 cells do?

Answer 22

• antibody production via B cells
• mast cell degranulation

Question 23

What does IL-4 and IL-13 form Th2 cells do?

Answer 23

• intestinal mcus secretion and peristalsis
• alternative macrophage activation

Question 24

What allows for eosinophil granules to escapethe eosinophil?

Answer 24

IgE and IL-5

Question 25

Th2 cytokines IL-4 & IL-13 inhibit...

Answer 25

classical macrophage activation

Question 26

What does the alternative activated macrophage path via Th2 cells do?

Answer 26

antiinflammatory effects

Question 27

Th1 cytokine IFNgamma inhibits...

Answer 27

Th2 and Th17

Question 28

Vasoactive amines and lipid mediators from Th2 cells and mast cells leads to?

Answer 28

immediate hypersensitivity reaction

Question 29

Cytokines from Th2 cells and mast cells leads to?

Answer 29

late-phase reaction

Question 30

Balance between Th1 and Th2 cell activation determines outcome of...

Answer 30

intracellular infections

Question 31

What is the major function of Th17 cells?

Answer 31

- Recruitment of neutrophils, resulting in inflammation - antimicrobial peptides - increased barrier integrity

Question 32

What are the signature cytokines of Th17?

Answer 32

IL-17, IL-22

Question 33

What travels through the synapse between the target cell and CD8+ cell?

Answer 33

perforin granzymes - activates apoptosis

Question 34

Host counter defense to reduced MHC class I display on cell surfaces

Answer 34

activation of natural killer cells