cytokines and mucosal

Question 1

What receptors do cytokines bind too?

Answer 1

cytokines bind to cytokine receptors NOT PRR’s.

note: each cytokine binds to its own cytokine receptor

Question 2

what are the three generalized categories of cytokines

Answer 2

1. interleukins
2. common named (such as TNF-alpha)
3. chemokines

Question 3

true or false, small concentrations of cytokine are needed to induce full effect

Answer 3

true, as long as the correct receptor is present

Question 4

what is the main effect of cytokine signalling?

Answer 4

transcription activation

Question 5

Explain the JAK - STAT pathway for cytokines

start with cytokine binding alpha chain cytokine receptor.

Answer 5

cytokines have two receptors: one alpha chain and one beta chain.

1. cytokine will come in and bind the alpha chain
2. this recruits the beta chain and they dimerize
3. this causes the intracellular JAK proteins to come together and also dimerize
4. the JAK proteins phosphorylate each other (auto-phosphorylation) which activates them
5. JAK proteins phosphorylate the cytoplasm tail of the receptors
6. this phosphorylation recruits STAT proteins which bind the phosphorylated tails
7. JAK protein phosphorylates the STAT protein which causes them to dimerize.
8. this complex goes to the nucleus and acts as a transcription factor.

Question 6

t or f, JAK = janus kinase

Answer 6

true

Question 7

what is autocrine, paracrine, and endocrine?

Answer 7

auto –> cytokines act on self
para –> cytokines diffuse and act nearby
endo –> cytokines enter blood and act at distance

Question 8

cytokines have 5 major roles. What are they?

Answer 8

1. initiate humoral and cell mediated responses
2. modulate inflammation
3. cell proliferation and differentiation (of hematopoietic stem cells)
4. hematopoiesis
5. wound healing

Question 9

name the cytokines that are: pro-inflammatory

Answer 9

IL-6
IL-1 beta
TNF-alpha

Question 10

name the cytokines that are: anti-inflammatory

Answer 10

IL-10

TGF-beta

Question 11

name the cytokines that are: T cell related

Answer 11

IL-2
IL-4
IL-12

2+4 = 6

Question 12

name the cytokines that are: B cell related

Answer 12

IL-4
IL-5
IL-7

Question 13

name the cytokines that are: interferons

Answer 13

IFN-1 –> alpha and beta units

IFN-2 –> only gamma units

Question 14

what are the major producers of pro-inflammatory cytokines?

Answer 14

macrophages and dendritic cells

Question 15

what is a cytokine storm

Answer 15

a cytokine storm is a massive release of pro-inflammatory cytokines which is un controlled. Can lead to tissue damage and organ failure.

Ebola causes this.

Question 16

what are the major producers of anti-inflammatory cytokines?

Answer 16

macrophages and T cells

Question 17

t or f, T cells play a big role in pro-inflammation

Answer 17

false, they release anti - inflammatory cytokines

Question 18

What produces IL-2, IL-4, and IL-12? what are their effects?

Answer 18

IL-2 -> T cells
IL-4 –> helper T cells
IL-12 –> macrophage and dendritic cells

all 3 support T cell proliferation and activation

Question 19

what are IL-4, IL5, and IL7 made from? what they do?

Answer 19

IL4 and IL5 are made by helper T cells

IL7 made by stromal cells (important in B cell maturation)

they all help B cell proliferation and differentiation

Question 20

t or f, cytokines have

pleiotropy
redundancy
synergy
antagonism

Answer 20

true,

synergy means one cyto only works in conjunction with another.

Question 21

t or f, cytokines can be produced by non immune cells

Answer 21

true

Question 22

what is inflammatory bowel disease?

Answer 22

this can occur if a microbe gets into our GI tract and manages to pass through our mucosal and endothelial lining. If our already present B cells, macrophages, dendritic cells cannot clear it then we may get an imbalance of cytokines in which too many pro-inflammation cytokines are released. This causes chronic inflammation

Question 23

how does the body counter IBD?

Answer 23

• macrophage or dendritic cell can produce IL-12 (not 2 or 4 which are made by T cells) which will help activate T cells. This allows T cells to produce anti-inflammatory cytokines such as TGF-beta and IL-10.
  etc.