Cytokine lecture Flashcards
What is a cytokine?
Proteins secreted by cells that mediate the functions of the immune system
-regulate the intensity and duration of the immune response
Are cytokines necessary for leukocyte activation?
yes
Where do cytokines come from?
From: lymphocytes monocytes/macrophages all cells of adaptive and innate immunity and some other cells
What does interleukin refer to?
It refers to the fact that one immune cell produces many proteins that act on neighboring cells (they work between cells)
Cytokines that attract cells are called _____.
Chemokines
Cytokine secretion is brief and _____ _____.
self-limited
Cytokine action is pleitropic and _____
redundant
T/F cytokines cannot act in synergy?
False they can
T/F cytokines cannot be antagonistic to each other
False they can
T/F cytokines influence each other.
true
Can cytokines act/work locally as well as systemically?
Yes
How is cytokine action initiated?
Via binding to specific membrane bound receptors
When a cytokine has the ligand/receptor interaction, what is the result?
gene expression that alters cellular function
The cytokines involved in innate immunity are typically responsible for what?
inflammation
Why are cytokines important for immunity?
They activate immune cells
They recruit immune cells to the site of infection
They help to activate the adaptive immune response
What is the principal mediator of the acute inflammatory response to gram-negative bacteria, endotoxic shock, and chronic inflammatory conditions?
TNF-a
What are the primary cells that make TNF-a
Monocytes, macrophages, NK cells, some DC cells and T cells
What is the role of TNF-a?
It stimulates the recruitment of neutrophils, monocytes, and activated T cells to the site of infection
High quantities of TNF-a leads to what?
septic shock, liver damage, blood clots in vessels
Moderate quantities of TNF-a leads to what?
Fever, liver loses acute phase proteins, hematopoiesis is affected
Low quantities of TNF-a leads to what?
it’s correct function- inflammatory response and recruiting other cells to the site of infection
What are the two forms of IL-1? Functionally, are they different?
IL-1a
IL-1b
Nope
Do the two form of IL-1 bind to the same receptor?
yes
What is a prominent job of cytokines in the innate immune system?
Inflammatory response
What is the job of cytokines?
Inflammatory response
T/F neutrophils produce IL-1?
True
IL-6 is primarily involved with what?
the induction of the acute phase response
What binds to bacteria to opsonize it?
CRP
Will CRP activate the complement cascade?
Yep
IL-1 and IL-6 are responsible for you feeling sick. What are some of those symptoms?
suppressed appetite mood altered immune response stimulated sleep stimulated fever stimulated
The immune system communicates with the brain through the production of _____.
cytokines
List of cytokines- which one is the stereotypical Th-1 cytokine?
IL-2
List of cytokines- which one is the stereotypical Th-1 cytokine?
IFN-y
Does IL-12 directly activate macrophages? If so, how? If not, why/how?
It does not.
IL-12 acts on many other cells- Th1, NK and CD8+ cells- and those cells produce IFN-y which activates the macrophages
IL-12 is the primary mediator of _____ immune response to intracellular _____.
innate
pathogens
List of cytokines- which one is the stereotypical Th-1 cytokine?
not sure…
Does IL-12 activate macrophages?
nope
How does the immune system communicate with the brain?
Via cytokines
IL-12 induces the production of what?
IFN-y
What are the three cells that can produce IFN-y?
NK cells
T helper cells
cytotoxic T cells
When a macrophage is activated, what can it do?
It can kill whatever it has already phagocytized
Which cytokines are involved with Th1 type immunity?
IFN-y and IL-2
Which cytokines are involved with Th2 type immunity?
IL-4,5,13, and 2
T/F most cytokines are produced by the adaptive immune system?
True- and it makes sense because how else are all the T cells going to get to the target site?
Which T helper cell is most effective with intracellular pathogens? Extracellular?
Intracellular: Th1
Extracellular: Th2
What is the primary function of IFN-y?
To all the macrophages to kill intracellular microbes
IL-4 induces what kind of cells?
More Th2 cells
IL-4 is the primary stimulus for _____ ______ to IgE.
Class switching to IgE
IL-5 works with what?
Eosinophils- parasite stuff
Eosinophil degranulation causes airway obstruction, so which cytokine would be involved in allergic reactions and asthma attacks?
IL-5
Which cytokine helps to inhibit/control the inflammatory response? How does it do it?
IL-10
It inhibits IL-12 production. IL-12 acts on multiple cell types, so if IL-10 can inhibit IL-12, a lot of work gets done.
Which cytokine is the most important for controlling inflammation?
IL-10
Type I and type II cytokine receptors signal via what type of cascade?
Jak-STAT
T/F all the chemokine receptors are 7 transmembrane G-protein coupled receptors?
True
