Cytokines

Question 1

What do cytokines trigger?

Answer 1

Activation, proliferation and differentiation of immune cells

Question 2

What type of signaling does IL-2 do?

Answer 2

Autocrine signaling - IL-2 released by CD4+ T helper cells acts on themselves
Paracrine signaling - IL-2 helps nearby CD8+ cytotoxic T cells proliferate

Question 3

What cytokines are produced by macrophages and dendritic cells?

Answer 3

IL-1 BETA, IL-6, TNF-ALPHA

Question 4

What does IL-1 BETA, IL-6, TNF-ALPHA do on the liver and brain cells?

Answer 4

Liver - stimulates production of CRP and Mannose-binding Lectin
Brain - causes a fever

Question 5

What cytokines made by dendritic cells recruit other immune cells to the site of infection?

Answer 5

IL-1 BETA and TNF-ALPHA enhance inflammatory response

Question 6

What are the 5 main classes of cytokines?

Answer 6

• Interleukins (ILs)
• Tumor Necrosis Factor (TNFs)
• Interferons (IFNs)
• Colony Stimulating Factors (CSFs)
• Transforming Growth Factors (TGFs)

Question 7

What are some examples of TNFs and their function?

Answer 7

TNF-ALPHA, TNF-BETA, Lymphotoxin-BETA
Activate endothelial cells to upregulate adhesive molecules and increase vascular permeability

Question 8

How many types of IFNs are there?

Answer 8

2, type I and type II

Question 9

Examples of Type I IFNs and their function

Answer 9

IFN - ALPHA and IFN - BETA
Produced by virally infected cells and dendritic cells to limit viral replication

Question 10

Example of Type II IFN and its function

Answer 10

IFN-GAMMA
Most powerful macrophage activator. Also activates CD4+ T helper cells which secretes own IFN-GAMMA and IL-2

Question 11

Example of CSF and its function

Answer 11

GM-CSF
Stimulates proliferation and differentiation of haemopoietic stem cells

Question 12

Example of TGF and its function

Answer 12

TGF-BETA
Inhibitory factor and suppresses proliferation and differentiation of immune cells.
Helps CD4+ T-cells become regulatory cells - suppress immune response

Question 13

What are the Pro-inflammatory cytokines?

Answer 13

INF-ALPHA and INF-BETA

Question 14

What is IL-12 and what does it do?

Answer 14

Secreted by macrophages and dendritic cells.
Activates NK cells.
Helps CD4+ helper cells differentiate into CD4+ Th1 cells.

Question 15

What does CD4+ Th1 cells secrete?

Answer 15

IFN-GAMMA and Lymphotoxin (LT-BETA)

Question 16

What interleukins help CD4+ helper cells differentiate into CD4+ Th17 cells?

Answer 16

IL-6, IL-23 and TGF-BETA

Question 17

What does CD4+ Th17 cells secrete?

Answer 17

IL-17, which recruits neutrophils to the site of inflammation

Question 18

What is the function of IL-17?

Answer 18

It recruits neutrophils to the site of inflammation

Question 19

What is IL-17 effective against?

Answer 19

Viruses, bacteria and cancers

Question 20

What interleukins are for parasitic infection?

Answer 20

IL-4, IL-5 and IL-13

Question 21

What do IL-4, IL-5 and IL-13 do?

Answer 21

Help against parasitic infection.
Stimulate differentiation of
T cells to Th2 Helper T cells, which activate mast cells, basophils and eosinophils

Question 22

What cytokines are used in the regulatory immune response?

Answer 22

IL-10 and TGF-BETA

Question 23

What do IL-10 and TGF-BETA do?

Answer 23

• Stimulate differentiation of T cells to T regulatory cells.
• T reg cells produce more of these cytokines and perpetuates anti-inflammatory state.
• Reduce expression of co-stimulatory receptors

Question 24

What does IL-7 do?

Answer 24

Helps the proliferation of lymphoid progenitor cells

Question 25

What do chemokines do?

Answer 25

Help cells move towards site of inflammation

Question 26

What does IL-8 do?

Answer 26

IL-8 is produced by neutrophils, macrophages and fibroblasts to recruit phagocytes to site of infection

Question 27

What are the main responses to cytokines?

Answer 27

• Acute inflammatory
• Pro-inflammatory
• Parasite/ allergy
• Regulatory
• Growth and differentiation
• Chemotactic agents