cytokines and mucosal Flashcards
What receptors do cytokines bind too?
cytokines bind to cytokine receptors NOT PRR’s.
note: each cytokine binds to its own cytokine receptor
what are the three generalized categories of cytokines
- interleukins
- common named (such as TNF-alpha)
- chemokines
true or false, small concentrations of cytokine are needed to induce full effect
true, as long as the correct receptor is present
what is the main effect of cytokine signalling?
transcription activation
Explain the JAK - STAT pathway for cytokines
start with cytokine binding alpha chain cytokine receptor.
cytokines have two receptors: one alpha chain and one beta chain.
- cytokine will come in and bind the alpha chain
- this recruits the beta chain and they dimerize
- this causes the intracellular JAK proteins to come together and also dimerize
- the JAK proteins phosphorylate each other (auto-phosphorylation) which activates them
- JAK proteins phosphorylate the cytoplasm tail of the receptors
- this phosphorylation recruits STAT proteins which bind the phosphorylated tails
- JAK protein phosphorylates the STAT protein which causes them to dimerize.
- this complex goes to the nucleus and acts as a transcription factor.
t or f, JAK = janus kinase
true
what is autocrine, paracrine, and endocrine?
auto –> cytokines act on self
para –> cytokines diffuse and act nearby
endo –> cytokines enter blood and act at distance
cytokines have 5 major roles. What are they?
- initiate humoral and cell mediated responses
- modulate inflammation
- cell proliferation and differentiation (of hematopoietic stem cells)
- hematopoiesis
- wound healing
name the cytokines that are: pro-inflammatory
IL-6
IL-1 beta
TNF-alpha
name the cytokines that are: anti-inflammatory
IL-10
TGF-beta
name the cytokines that are: T cell related
IL-2
IL-4
IL-12
2+4 = 6
name the cytokines that are: B cell related
IL-4
IL-5
IL-7
name the cytokines that are: interferons
IFN-1 –> alpha and beta units
IFN-2 –> only gamma units
what are the major producers of pro-inflammatory cytokines?
macrophages and dendritic cells
what is a cytokine storm
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.
what are the major producers of anti-inflammatory cytokines?
macrophages and T cells
t or f, T cells play a big role in pro-inflammation
false, they release anti - inflammatory cytokines
What produces IL-2, IL-4, and IL-12? what are their effects?
IL-2 -> T cells
IL-4 –> helper T cells
IL-12 –> macrophage and dendritic cells
all 3 support T cell proliferation and activation
what are IL-4, IL5, and IL7 made from? what they do?
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
t or f, cytokines have
pleiotropy
redundancy
synergy
antagonism
true,
synergy means one cyto only works in conjunction with another.
t or f, cytokines can be produced by non immune cells
true
what is inflammatory bowel disease?
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
how does the body counter IBD?
- 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.
