Cytokines (midterm)

Question 1

What are the type I interferons?

Answer 1

• IFN-α
• IFN-β

Question 2

What are the type II interferons?

Answer 2

• IFN-γ

Question 3

What cells secrete type I interferons?

Answer 3

• Plasmacytoid dendritic cells in response to viruses
• Conventional dendritic cells, macrophages, B cells, endothelial cells as a consequence of TLR3/TLR4 activation

Question 4

What is the function of type I interferons?

Answer 4

• Sequestration of lymphocytes in secondary lymphoid organs
  The antiviral state:
• Increased cytotoxicity of CD8⁺ T cells/NK cells
• Upregulation of MHC-I proteins
• Decreased RNA translation
• Increased activity of RNAases
• Increased activity of GTPases

Question 5

Which cytokines are responsible for the antiviral state?

Answer 5

Type I interferons (IFN-α, IFN-β)

Question 6

What cells secrete type II interferons?

Answer 6

• NK cells
• CD4⁺ T_H1 cells

Question 7

What is the function of type II interferons?

Answer 7

• Classical (M1) activation of macrophages to kill intracellular pathogens
• Class-switching of B cells to IgG

Question 8

Which cytokines are responsible for classical (M1) activation of intracellular pathogens?

Answer 8

Type II interferons (IFN-γ)

Question 9

Which cytokines are responsible for class-switching to IgG?

Answer 9

Type II interferons (IFN-γ)

Question 10

Which cells secrete tumor necrosis factor (TNF)?

Answer 10

• NK cells
• Macrophages
• Dendritic cells
• Not epithelia or neutrophils
  (All via the action of TLRs, NLRs, or RLRs)

The fact that TNF is not produced by epithelia or neutrophils is the main difference between TNF and IL-1

Question 11

What are the functions of TNF?

Answer 11

• Increasing NK cell cytotoxicity
  Local inflammatory effects:
• Increasing expression of adhesion molecules on endothelial cells
• Stimulation phagocytes to release cytokines and chemokines for inflammation and leukocyte chemotaxis
  Systemic protective effects:
• Fever
• Stimulating leukocyte production in the bone marrow
  Systemic pathologic effects:
• Decreased cardiac output
• Formation of thrombi in blood vessels
• Insulin resistance in skeletal muscle

Question 12

Which cytokines are responsible for induction of fever?

Answer 12

• TNF
• IL-1
• IL-6

Question 13

Which cytokine increases the cytotoxicity of NK cells?

Answer 13

TNF

Question 14

Which cytokines are responsible for increased production of acute phase proteins?

Answer 14

• IL-1
• IL-6

Question 15

Which cytokines increase expression of adhesion molecules on endothelial cells?

Answer 15

• TNF
• IL-1

Question 16

To which family of cytokines does BAFF (BLyS) belong?

Answer 16

Tumor necrosis factors

(Not sure if this is required)

Question 17

What is the function of BAFF (BLyS)?

Answer 17

Preventing activated B cell death

Question 18

What is the function of Bcl-2?

(Not a cytokine)

Answer 18

An anti-apoptotic protein in B cells
Damage to the BCL2 gene is implicated in chronic B lymphocytic leukemia

Question 19

Which cells secrete IL-17?

Answer 19

CD4⁺ T_H17 cells

Question 20

What is the function of IL-17?

Answer 20

Leads to recruitment of macrophages and neutrophils (via release of other cytokines)

Question 21

What cells secrete IL-12?

Answer 21

• Macrophages
• Dendritic cells

Question 22

What is the function of IL-12?

Answer 22

Activation of NK cells

Question 23

What is the receptor through which NK cells are activated?

Answer 23

FcγRIIIA

Question 24

What is the receptor through which basophils, eosinophils, and mast cells are activated?

Answer 24

FcεRI

Question 25

What cells secrete IL-15?

Answer 25

* Macrophages * Dendritic cells

Question 26

What is the function of IL-15?

Answer 26

Activation of NK cells

Question 27

What cells secrete IL-4?

Answer 27

CD4⁺ T_H2 cells

Question 28

What is the function of IL-4?

Answer 28

* M2 activation of macrophages * Class-switching to IgE

Question 29

What cells secrete IL-13?

Answer 29

CD4⁺ T_H2 cells

Question 30

What is the function of IL-13?

Answer 30

M2 activation of macrophages

Question 31

What cells secrete IL-13?

Answer 31

CD4⁺ T_H2 cells

Question 32

What is the function of IL-13?

Answer 32

M2 activation of macrophages

Question 33

What cells secrete IL-18?

Answer 33

* Macrophages * Dendritic cells * Neutrophils * Some epithelial cells (Via action of the NLRP class of NLRs)

Question 34

What is the function of IL-18?

Answer 34

Pro-inflammatory mediator

Question 35

What cells secrete IL-1?

Answer 35

* Macrophages * Dendritic cells * **Neutrophils** * **Epithelial cells** (Via the combined action of NLRs and TLRs)

Question 36

What are the functions of IL-1?

Answer 36

**Local inflammatory effects:** * Increasing expression of adhesion molecules on endothelial cells * Stimulation phagocytes to release cytokines and chemokines for inflammation and leukocyte chemotaxis **Systemic protective effects:** * Fever * Production of acute phase proteins * Stimulating leukocyte production in the bone marrow **Systemic pathologic effects:** * Insulin resistance in skeletal muscle

Question 37

What cells produce IL-6?

Answer 37

* Macrophages * Dendritic cells * Neutrophils * Epithelial cells

Question 38

What is the function of IL-6?

Answer 38

* Promotes formation of T_H17 cells **Systemic protective effects:** * Fever * Production of acute phase proteins * Stimulating leukocyte production in the bone marrow

Question 39

What is the function of IL-8?

Answer 39

CXCL8—promotes chemotaxis and phagocytosis

Question 40

What cells secrete IL-8?

Answer 40

* Macrophages * Epithelial cells * Endothelial cells * Airway smooth muscle cells

Question 41

What is the ligand of CXCR5?

Answer 41

CXCL13

Question 42

What cells secrete CXCL13?

Answer 42

Follicular dendritic cells

Question 43

What is the receptor for CXCL13?

Answer 43

CXCR5

Question 44

What is the ligand for CCR19/CCR21?

Answer 44

CCL7

Question 45

What is the receptor for CCL7?

Answer 45

CCR19/CCR21

Question 46

Where does the gradient of CXCL13 lead?

Answer 46

Secondary follicles (B cell zones)

Question 47

Where does the gradient of CCL7 lead?

Answer 47

Marginal zone of T cell zone

Question 48

What is the function of transforming growth factor beta (TGF-β)

Answer 48

Class-switching to IgA