Lecture 22 - Cytokines and Chemokines

Question 1

Cytokine definition

Answer 1

Small molecules, either proteins or peptides, that upon release and binding to specific receptors elicit an immune response

Question 2

Feature that is widespread among cytokine receptors

Answer 2

Mutimeric

Question 3

Example of a cytokine that requires transpresentation

Answer 3

IL-15

Won’t elicit a response unless bound to IL-15R alpha

Question 4

Why can IL-15 only affect nearby cells?

Answer 4

Must be bound to IL-15R alpha in order to generate a response
This can only occur near secreting cell

Question 5

Number of proteins in TNF superfamily

Answer 5

19

Question 6

Two major biological functions of TNF superfamily

Answer 6

1) Pro-inflamamtory (TNF, TRAIL, BAFF)

2) Cell survival, growth (NGF, FasL)

Question 7

TNFalpha
1)
2)
3)

Answer 7

1) Strong pro-inflammatory molecule
2) Major pathological factor in rheumatoid arthritis
3) Belongs to TNF superfamily

Question 8

Cachexia

Answer 8

Wasting

Question 9

TNF actions
1)
2)
3)
4)

Answer 9

1) Neutrophil activation
2) Catabolic metabolism
3) Apoptosis
4) Perpetuation of pro-inflammatory cytokine loops

Question 10

Common gamma-chain cytokines
1)
2)
3)
4)
5)
6)

Answer 10

1) IL-2
2) IL-4
3) IL-7
4) IL-9
5) IL-15
6) IL-21

Question 11

What is the common gamma chain?

Answer 11

CD132

Question 12

What do mutations in the CD132 gene lead to?

Answer 12

SCID

Question 13

Signal transduction pathway used by common gamma chain interleukin receptors

Answer 13

JAK/STAT

Question 14

IL-2 function
1)
2)
3)
4)

Answer 14

1) T cell growth factor
2) Augments NK cell function
3) Promotes B cell antibody production
4) Assists in Treg development

Question 15

IL-4 function
1)
2)
3)

Answer 15

1) Th2 bias, function
2) Class switching to IgE
3) Mast cell activation

Question 16

Il-7 role

Answer 16

Critical role in T cell development

Absence of IL-7 results in absence of T cells in SCID patients

Question 17

IL-9 role
1)
2)
3)

Answer 17

1) Activation of epithelial cells
2) Activation of B cells
3) Activation of eosinophils, mast cells

Question 18

IL-15 role
1)
2)

Answer 18

1) NK cell development - Absence of IL-15 responsible for NK cell absence in SCID patients
2) T cell homeostasis

Question 19

IL-21 role
1)
2)
3)

Answer 19

1) important for Tfh cells
2) Stimulates B cell responses in germinal centres
3) Sustains CD8+ response in infections

Question 20

Chemokines
1)
2)
3)
4)

Answer 20

1) Very small peptides (8-12kD)
2) Use GPCR as signal transduction pathway
3) Classified on the basis of cysteine residues in N-terminal (CC, CXC)
4) ~50 known chemokines

Question 21

Key cytokine funcitons
1)
2)
3)

Answer 21

1) Recruitment of circulating leukocytes from blood to tissues
2) Regulate traffic of lymphocytes to and within lymphoid organs
3) Regulate migration of DCs from tissues to lymph nodes

Question 22

Expression pattern of CCL19, CCL21

Answer 22

Constitutive

Question 23

What produce CCL19, 21?
1)
2)

Answer 23

1) Stromal cells of the lymph node

2) Endothelial cells in HEV

Question 24

What do stromal cells of the lymph node and endothelial cells of the HEV produce?

Answer 24

CCL19, CCL21

Question 25

What express CCR7?

Answer 25

Naive T cells, naive B cells, DCs

Question 26

How do cells follow chemokine gradient?

Answer 26

By amoeboid movement

Question 27

What does a DC express when it phagocytoses and antigen?

Answer 27

CCR7

This causes it to begin moving into the lymph, towards a lymph node