Cytokines, Chemokines, and Their receptors Flashcards
what is a cytokine
protein that mediates the functions of the immune resonse
what type of cells can produce cytokines
- lymphocytes
- macrophages
- all cells of innate and adaptive immune systems
- tons of cells*
cytokines that attract cells are known as
chemokines
in general, cytokine secretions are _____ and ______
brief and self-limited
The action of cytokines is said to be pleitropic and redundant, what does this mean
means cytokines elicit multiple different effects, and that 2 diff. cytokines can signal for the same effect
Cytokines are A) synergistic B) antagonistic or C) Both
C both
T/F the production of one cytokine Does NOT influence other cytokines, they only act on themselves
False, cytokines influence eacthother dramatically
Cytokines can act locally and systemically, what are the 2 secretion stratagies that secrete locally and what secretion strategy acts systemically
Locally - paracrine and autocrine
Systemically - endocrine
how do cytokines initiate their actions
by binding to specific membrane receptors
cytokine receptor-ligand ligation results in ________ which in turn causes cellular action
gene expression
what pro-inflammatory cytokine of the innate immune response is the principle mediator of the inflammatory response
TNF-alpha
TNF-alpha is part of the innate immune response and can have 4 downstream effects, what are they
1 - increase selectin ligand expression
2 - increase P and E selectin expression
3 - increase chemokine expression
4 - increase integrin ligand expression
T/F No matter what the quantitiy of TNF-alpha produced, it will always result in beneficial effects
False, to much production of TNF-alpha = sepsis
IL-1 has is a pro-inflammatory cytokine of the innate immune response and has the same effects as _____
TNF-alpha
example of redundancy of cytokines*
what are some characteristics of IL-6 ?
- pro-inflammatory cytokine of innate immunity
- involved in induction of acute phase of inflammatory response
during an infection what causes you to feel sick ?
Increase in production of cytokines cause feelings of sickness b/c they travel to brain
IL-12 is part of the innate immune response, what is it role ?
- primary mediator of intracellular pathogens
- production of Th1 immunity
IL-12 leads to production of what type of helper t cells, and what type of immunity do these cells promote
type 1 helper t cells (Th1)
-promote cell-mediated immunity against intracellular pathogens
IL-12 induces the production of _______
INF-gamma
what cytokines are involved with Th1 type immunity (cell-mediated) ?
IFN-gamma, (IL-12)
protect against intracellular pathogens*
what cytokines are involved with Th2 type immunity (humoral) ?
IL-4, IL-5, IL-13, (IL-2)
all fight against extracellular pathogens*
which cytokines are considered part of the innate immunity and considered inflammatory cytokines
TNF-alpha
IL-1
IL-6
Th1 cells protect against _____ pathogens whereas Th2 cells protect against _______ pathogens
Th1 - intracellular
Th2 - extracellular
what cytokines are considered part of the adaptive immunity
IL-2, IL-4, IL-5, IL-13
IL-2 is primarily needed for what ?
Growth/clonal expansion of T cells
IFN-gamma is produced by _______ and has what 4 functions ?
- IL-12
1) activate macrophages
2) increase opsonization
3) increase Ag presentation
4) enhance microbicidal activity
what is the key Th2 cytokine, and what does it do ?
IL-4, induces naive T cells to differentiated Th2 cells
what 2 cytokines promote isotype or class switching to IgE
IL-4 and IL-13
what is the function of IgE
binds to parasites and destroys extracellular pathogens
IL-13 is very similar to _____ and is responsible for stimulating mucous production in the gut and lung to decrease parasites
IL-4
what is the primary role of IL-5
production of eosinophils to fight off parasites
what cytokine is involved in allergic responses
IL-5
what is the inhibitory cytokine ? and what does it inhibit ?
IL-10
-inhibits the production of IL-12 which would decrease IFN-gamma = decreased cytotoxic activty
what is the primary role of chemokines
regulate migration of cells (chemotactic cytokines)
chemokines are classified based on the number and location of ?
N-terminal cysteine residues
in nomenclature of chemokines, it is important to remember that chemokine subclass bind/match to what ?
receptor subclass EX: CXC chemokines bind to CXC chemokine receptors
chemokine ligands are loyal and chemokine receptors are sluts, what does this mean ?
chemokine ligands only bind to its ONE specific receptor whereas receptor can bind with multiple diff. ligands
activated immune cells follow a ____________ in order to get to the site of infection
chemokine gradient
what are the 5 receptor families for chemokines and cytokines
Type 1 cytokine receptor Type II cytokine receptor TNF receptor IL-I receptor G protein coupled receptor
how are the different families of receptors for chemokines and cytokines distinguished
based upon their extracellular binding domain and intracellular signalling domain
what cytokines are in the Type I cytokine receptor family
IL-2, IL-4, IL-5, IL-6, IL-12, IL-13
what is the intracellular signaling pathway for Type I cytokine receptors
Jak-STAT cascade
what cytokines are in the type II receptor family
IFN-gamma, IL-10
what intracellular signal pathway does type II cytokine receptors use
Jak-STAT pathway
what cytokine are in the TNF receptor family and what signal cascades do they use
TNF-alpha
-use multiple signal cascades that can lead top apoptosis
what cytokine uses the IL-I receptor family, and what is its intracellular signalling pathway
IL-1alpha or IL-1Beta
-uses IRAK activating cascade
what receptor family is very similar to Toll-like receptors
IL-1
what cytokines use the the G-protein coupled receptor family, and how many transmembrane protein receptors are present in all G protein receptors
All chemokines
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