Chemokines

Question 1

What are the properties of cytokines?

Answer 1

They regulate host defenses against disease and inflammation
Can be sequestered or membrane bound
Regulate other cell’s activities by acting on signalling cascae which will regulate apoptosis, differentiation, growth
Acts on specific receptos

Question 2

How are IL-2 and IL-15 SIMILAR

Answer 2

They both act on t-cells and induce their growth

Question 3

True or false

Cytokines are homologous

Answer 3

false

Question 4

How many families of cytokine receptors are there? State two of them their structure, function and members, features

Answer 4

6
TNF receptor-TNF-R, CD40, fibronectin DD, cystolic domain jelly roll motif, pro-inflammatory
chemokine receptor-7TM, IL8, chemotactic, triple stranded and b-sheets

Question 5

Interaction between cytokines, what does it depend on?

Answer 5

It depends on the type of infection. If it’s viral then TH1 will be activated, if it’s extracellular infection then TH2 will be activated

Question 6

How do TH1 and TH2 regulate each other? How do they work with each other

Answer 6

By releasing the activators they suppress the activity of the other TH activator.
Using transcription factors can adapt to the other TH and work with it, ifn it’s in the corresponding environment

Question 7

What cytokines are produced when TH1 is activated? What cytokines activate it?
What inhibits it?
When is TH1 activated?
WHat is an example of transcription factors?

Answer 7

IL-12, CD28
IFN, Il-2
IL-10,IL4
Inflammation . or organ specific immunity, viral infection, T-BET,NFK-B

Question 8

What cytokines are produced when TH2 is activated? What cytokines activate it?
What inhibits it?

Answer 8

IL-4
IL4,5,9,10,13
IFN-G
GATA-3
Humoural immunity,allergy

Question 9

How does cancer mediate and suppress immune response?

Answer 9

By expressing fas ligand, granzymes, perforin which will kill t-cells
creates a tolergenic environment by releasing tgf-b and activating myeloid suppressor cells and release chemokines that repel the t-cells from the environment

Question 10

Give examples of cytokines that are always released?

Answer 10

g-csf,m-csf, il-6

Question 11

Give examples of cytokines that are always presynthesized and stored in granules?

Answer 11

tgf-b

Question 12

Give examples of cytokines that are always stored in membranes?

Answer 12

tnf-a,tgf-a

Question 13

cytokines complexed in cell surface or ECM?

Answer 13

TGF-B, IL-8

Question 14

How are cytokines regulated?

Answer 14

By enzymes processing their precursor forms

Question 15

How do IL-8 work?

Answer 15

By binding to endothelial cells GAG and homing the leukocyte to the inflammatory site

Question 16

How do chemokines recruit leukocyteS?

Answer 16

They create a concentration dependent gradient where cytokines are in hugh levels in the ECM near the inflammation site and secreted at low levels in the overlying endothelial cells, the leuocyte bind to the selectin and roll on the tissue where they come into contact with the chemokine on the heparan sulphate and this activates the integrin and this causes it to fully adhere and extravasate into tissue where it can carry out it’s effector functions
They recruit it by creating gradients and pro-inflammatory sites

Question 17

What cytokine are released during last stages?

Answer 17

interferon gamma, interleukin 1, tumour necrosis factor

Question 18

What is the role of IL-8 in cancer? What would inhibit these processes

Answer 18

Can promote metastasis and angiognesis.

Platelet factor 4 and IL-10

Question 19

What are they 5 symptoms of advanced cancers and what are the 3 main cytokines associated with cachexia?

Answer 19

TNF, IL-6, IL-1, IFN gamma

Decreased thirst and loss of appetite, weight loss, hypertension, hypoglycaemia or hyperglycemia, fever

Question 20

How many families of chemokines are there? What are their characteristics?

Answer 20

4

alpha(CXC) and beta(CC);4cystines

Question 21

t/f
Chemokine receptors are G protein-coupled proteins that
are expressed on subgroups of leukocytes

Answer 21

T