Cytokines

Question 1

Cytokines’ functions

Answer 1

Hematopoyesis (IL-3)
Lymphocyte growth and differentiation
Activation of effector cells for pathogen clearance

Question 2

General properties

Answer 2

1. Pleiotrophism
2. Redundancy
3. Self-limited action
4. Produced briefly
5. Either local or systemic actions
6. Coordination of signal cascade
7. 1 Effect on cytokine synthesis
8. 2 Effect on cytokines actions (Synergism and antagonism)
9. Receptors with high affinity
10. Regulation of theiracions via different receptors expression

Question 3

Example ofeffects on cytokine synthesis

Answer 3

1. INF-Y expression
2. Macrophage activation
3. IL-2 production
4. T H cell differentiation
5. Production of different cytokines (IFN-Y, IL-2…)

Question 4

Innate immunity cytokines examples

Answer 4

• TNF-alpha
• IL-1
• IL-12
• INF-Y (BOTH)

Question 5

Source, stimunli, inhibition and main actions of innate immunity cytokines

Answer 5

• Source: DCs, macrophages ad nKs
• Function: Mediate innate immunity and inflammation
• Stimuli: Bacterias, LPS and viral nucleic acids
• Inhibited by corticoids

Question 6

Adaptive immunity cytokines

Answer 6

IL-2, IL-4 and IFN-Y

Question 7

Source, actions, inhibition and stimuli of adaptive immunity cytokines

Answer 7

• Source: T cells
• Main actions: Lymphocyte differentiation and growth / Activation of effector cells
• Stimuli: Proteic antigens
• Inhibited by cyclopsorine and FK-506

Question 8

TNF alpha

Answer 8

Innate response
Produced by macrophages after recognising LPS in GN bacteria
Stimulated by IL-12
Local infection: Acute localised response (neutrophils and monocytes)

Systemic infection: Septic shock in high concentrations and fever & leukocytes inmoderate ones

Question 9

IL-12

Answer 9

Innate immunity
Main mediator of innate immunity against intracellular pathogens (activation of Th1)
Connection of adaptive and innate immunities
Stimulation of IFN-Y by NK and T cs
Produced by macrophages and DCs as a response to PAMPs, CD40L, IFN-Y

Question 10

IFNs (I)

Answer 10

Alpha and beta
Upregulation of MHC-I and immunomodulation of cells
Early innate antiviral immune response

Question 11

IL-2

Answer 11

Adaptive immunity
T cell growth factor
Regulated by antigen encounter
Produced mainly by CD4 T cells (also by CD8)
Proliferation of NK and B cells

Question 12

IFN-Y

Answer 12

Adaptive immunity but also innate
Macrophage anctivation
Produced by CD4, CD8, NK, Th1

Question 13

IL-4

Answer 13

Adaptive immunity
Synthesis of IgE and Th2 development
Produced by Th2 CD4 cells, mast cells and basophils