CYTOKINES

Question 1

IL-1 is produced by _______.
It functions to upregulate the expression of _____ on endothelial cells to increase adhesion of immune cells to the endothelium. It is also involved in _____ response.

Answer 1

IL-1:

• produced by macrophages
• upregulates VCAM-1 on endothelial cells
• involved in fever response

Question 2

IL-2 is produced by _____.

Function:

Answer 2

IL-2:

• produced by T-cells
• induces T cell and NK cell proliferation

Question 3

IL-4 is produced by _____ cells.

It mediates ____ synthesis and induces Th2 cell development.

Answer 3

IL-4:

• produced by Th2 cells
• mediates IgE synthesis (Class switching)

Question 4

_____ is produced by _____ cells and it mediates eosinophils terminal differentiation. It also induces Th2 cell development by ___ class switching.

Answer 4

IL-5:

• produced by Th2 cells
• eosinophil terminal differentiation (against parasites and allergy)
• IgA class switching

Question 5

IL-6 is produced by ____ cells. It induces the synthesis of ________ and _____ response.

Answer 5

IL-6:

• produced mainly by macrophages
• induces synthesis of acute phase proteins
• involved in fever response

Question 6

IL-8 is a ________ chemokine and it also stimulates the ______ response.

Answer 6

IL-8:

• neutrophilic chemokine (i.e. guides neutrophils to the site of infection)
• fever response

Question 7

IL-9 is produced by ____ cells and it mediates _____ maturation.

Answer 7

IL-9:

• produced by Th2 cells
• mast cell maturation

Question 8

IL-10 is an anti-inflammatory cytokine which induces _______ cell development.

Answer 8

IL-10:

• anti-inflammatory
• induces Treg cell development

Question 9

IL-12 is produced by _____ cells.

It functions to activate _____ and ____ cells.

Answer 9

IL-12:

• produced by Th1 cells
• activates NK cells and T cells
• increases IFN-y production by Th1 cells

Question 10

IL-13 is produced by ____ cells.

It mediates _____ synthesis and allergic hyperresponsiveness. It also functions to activate macrophages.

Answer 10

IL-13:

• produced by Th2 cells
• mediates IgE synthesis and allergic hyperresponsiveness
• activates macrophages

Question 11

IL-17 and IL-22 are produced by ____ cells.

They mediate the production of _______ and ________ chemokines by epithelial cells.

Answer 11

IL-17 and IL-22:

• produced by Th17 cells
• mediates production of defensins and neutrophilic chemokines by epithelial cells

Question 12

IFN-y is a type __ interferon and it is produced by ______ cells.
It has anti-viral properties. It also inhibits ____ synthesis and stimulates ____ response.

Answer 12

IFN-y:

• type 2 interferon produced by immune cells only
• anti-viral properties
• fever response
• inhibits IgE synthesis

Question 13

_____ is produced by activated macrophages. It stimulates T cell differentiation and upregulates the expression of adhesion molecules. It also stimulates the fever response.

Answer 13

TNF-a (tumor necrosis factor)

- involved in systemic inflammation

Question 14

______ is anti-inflammatory. It induces Th17 cells and inhibits T cell activation, dampening allergen-specific response.

Answer 14

TGF-B (transforming growth factor)

- anti-inflammatory

Question 15

Function of CXCL2?

Answer 15

CXCL2 is a chemokine that is used to recruit macrophages to the site of infection.

Question 16

6 main cytokines that Th1 cells secrete and their main functions:

Answer 16

1. IFN-y: activates macrophages to destroy phagocytosed bacteria
2. TNF-a: upregulates adhesion molecules on endothelium
3. IL-2: T-cell proliferation
4. CXCL2: chemokine to recruit more macrophages at the site of infection
5. Fas ligand: Kills infected cells
6. IL-3: induce macrophage differentiation in the bone marrow

Question 17

Which group of T-helper cell is involved in immune response against parasites and allergies?

Answer 17

Th2 cells

• secrete IL-5: eosinophil differentiation
• secrete IL-4 and IL-13: IgE synthesis (which binds to Fc receptors on the mast cells and to parasites)

Question 18

CTLA-4 is secreted by ____ cells. It binds to ______ and _____ on _______ cells to downregulate its expression and prevent T-cell co-stimulation.

Answer 18

CTLA-4:

• secreted by Treg cells
• binds to CD80 and CD86 on dendritic cells, preventing binding to CD28 on T cells and therefore co-stimulation of T-cells => regulates inflammatory response

Question 19

5 cytokines involved in the fever response:

Answer 19

Mainly:
IL-1 and TNF-a

Others:
IL-6, IL-8 and IFN-y

Question 20

4 acute phase proteins (which mainly functions to bind iron and starve bacteria):
Ferritin, Hepcidin, Ceruloplasmin, Haptoglobin

Answer 20

Ferritin - binds free iron

Hepcidin - downregulates ferroportin expression to prevent release of iron from cells

Ceruloplasmin - oxidises iron

Haptoglobin - binds haemoglobin

Question 21

Complements are mainly produced in the ______.

Answer 21

liver

Question 22

Complement proteins which are known as anaphylatoxins (able to carry out inflammation) are:

Answer 22

C3a, C4a and C5a

Question 23

The 3 pathways of the complement system converges at ____ (which is the principle opsonin) to form the ____.

Answer 23

converges at C3b

forming the MAC (membrane-attack complex)

Question 24

PD-1 is released by _____ cells to regulate T-cell activity.
PD-L1 (ligand) and antibodies to PD-1 are administered to release immune suppression for tumours.

Answer 24

Treg cells

Question 25

Macrophages produce 5 main kinds of cytokines.

Answer 25

IL1, TNF-a, IL6, IL8 and IL12