Important cytokines

Question 1

IL-1

Answer 1

Alarm cytokine, fever

Question 2

TNF-alpha

Answer 2

Alarm cytokine

Question 3

Alarm cytokines

Answer 3

IL-1, TNF-alpha
Function: released by activated macrophages; massive increase in vascular permeability–>severe drop in blood pressure which could be fatal (SEPTIC SHOCK)

Question 4

IL-6

Answer 4

Triggers acute phase protein production from LIVER

Question 5

IL-8

Answer 5

Chemotactic for neutrophils

Question 6

IL-12

Answer 6

Directs adaptive immunity, activates NK cells

Question 7

What activates NK cells?

Answer 7

IL-12,

IFN (all types)

Question 8

Functions of Th1 cells

Answer 8

1. Macrophage activation
2. DTH
3. Help for CD8 cells
4. Downregulation of Th2 responses

Question 9

Th1 macrophage activation cytokines

Answer 9

IFN-gamma, TNF-a

Question 10

Th1 DTH cytokines

Answer 10

IL-2, IFN-g, TNF-a, IL-3, GM-CSF

Question 11

Th1 CD8 help cytokines

Answer 11

IL-2

Question 12

Th1 downregulation of Th2 responses cytokine

Answer 12

IFN-g

Question 13

Th2 functions

Answer 13

1. B cell proliferation
2. B cell differentiation and Ig class switch
3. Downregulation of TH1 responses

Question 14

Th2 B cell prliferation cytokines

Answer 14

IL2, IL-4, IL-5

Question 15

Th2 B cell differentiation and Ig class switch cytokines

Answer 15

IL-2, IL-4, IL-5, IFN-g

Question 16

Downregulation of Th1 response by Th2 cytokine

Answer 16

IL-4

Question 17

Cytokines produced by Th-17

Answer 17

-IL-17
• Protective against some bacterial infections; clear bacterial infections through activation of neutrophils and macrophages
Mediate pathogenic responses in autoimmune diseases such as arthritis

Question 18

Follicular T helper cells

Answer 18

Produce IL-21
• reside in B cell follicles and induce B cells to produce antibodies
• Essential for generation of isotype-switched antibodies
• Triggers formation of germinal centre
Tfh (Follicular helper T cells)
• (B cell moves to edge of follicle and Tfh expressed CD40L, secretes IL-21 and IL-4 –> trigger formation of germinal centres –> affinity maturation)

Question 19

4 mechanisms of peripheral tolerance

Answer 19

RAID

Question 20

Cytokines produced by Treg

Answer 20

IL-10
TGF-B
IL 35

Question 21

TF in Treg

Answer 21

FOXP3

Question 22

Treg cells mechanisms

Answer 22

• secretion of immunesuppressive cytokines
• inactivation of DC or responding lymphocytes
• absorb IL-2 produced by DC (express IL-2 receptor)

Question 23

Th1 vs Th2

Answer 23

Th1=pro inflammatory

Th2=pro allergic

Question 24

IL-10

Answer 24

• Key anti-inflammatory cytokine
  
  • Multi-functional
  • Acts on RANGE of cells which have IL-10 receptor
  • BLOCKS pro-inflammatory cytokine synthesis (e.g. TNF, IL-6, IL-8, IFN gamma)
  • Downregulates macrophages
  • BUT viruses such as EBV mimic IL-10 action :(

Question 25

Cytokine cross-regulation

Answer 25

• Th1 inhibits Th2 and vice versa (they ONLY inhibit the other!)
• Th17 and Tregs inhibit ALL others
• all have self-positive feedback i.e. they produce cytokines that stimulate the same T cell to produce more of that cytokine

Question 26

Cytokines and macrophages

Answer 26

Different cytokines trigger development of DIFF macrophages (proinflammatory vs antiinflammatory)- can focus the TYPE of response