Cytokines

Question 1

proteins secreted by cells that mediate the functions of the immune system

Answer 1

cytokines

Question 2

cytokines are ____ proteins/glycoproteins, they regulate the ___ and ____ of the immune response, and they are necessary for _____

Answer 2

soluble; intensity; duration; leukocyte activation

Question 3

cellular sources of cytokines

Answer 3

• lymphocytes
• monocytes/macrophages
• all cells of innate immunity
• all cells of adaptive immunity
• endothelial/epithelial cells

Question 4

cytokines that attract cells

Answer 4

chemokines

Question 5

cytokine secretion is ____ and ____

Answer 5

brief; self-limited

Question 6

cytokine action is ____ and ____

Answer 6

pleitropic; redundant

Question 7

cytokines ____ eachother and can act ____ and ____

Answer 7

influence; locally; systemically

Question 8

cytokines initiate their actions by:

Answer 8

binding to specific membrane-bound receptors

Question 9

cytokine receptor ligation leads to ____ which alters ____

Answer 9

gene expression; cellular function

Question 10

3 signaling types of cytokines

Answer 10

autocrine, paracrine, endocrine

Question 11

example of autocrine signaling

Answer 11

IL-2 is needed for T cells to start proliferating; when T cells are activated, they make IL-2

Question 12

most cytokines do ____ signaling, in which one cell produces cytokine, and then cytokine acts on neighboring cells

Answer 12

paracrine

Question 13

all ____ and some cytokines, for example, ____, are capable of doing endocrine signaling, in which cytokine is released into bloodstream

Answer 13

chemokines; TNFalpha

Question 14

cytokines primarily involved in innate immunity typically impact ____

Answer 14

inflammation

Question 15

proinflammatory cytokines

Answer 15

TNFalpha
IL-1alpha/beta
IL-6
IL-12
IFN

Question 16

anti-inflammatory cytokines

Answer 16

IL-10

TGF-beta

Question 17

The principal mediator of the acute inflammatory response to Gram-negative bacteria (as well as other infectious microbes), endotoxic shock, and chronic inflammatory conditions

Answer 17

TNF-alpha

Question 18

primary cellular sources of TNF-alpha

Answer 18

monocytes, macrophages, NK cells, some dendritic cells, and T cells

Question 19

TNF-alpha stimulates recruitment of ? to site of infection

Answer 19

neutrophils, monocytes, and activated T cells

Question 20

TNF-alpha activates ____ first and then increases the expression of ____ and ____; TNF-alpha then increases the expression of integrin ligands, _____

Answer 20

leukocytes; E-selectin and P-selectin; VCAM-1 and ICAM-1

Question 21

____ concentrations of TNF-alpha in blood plasma can be beneficial

Answer 21

low (approx 1 nM)

Question 22

moderate concentrations (10-50 nM) of TNF-alpha in blood plasma can have ____ effects, but they are often ____

Answer 22

systemic; beneficial

Question 23

___ concentrations of TNF-alpha in blood is bad

Answer 23

high (>100 nM)

Question 24

primary producers of IL-1

Answer 24

mononuclear phagocytes (i.e. monocytes/macrophages, dendritic cells) and neutrophils

Question 25

IL-6 primarily produced by ___ and ____

Answer 25

macrophages; T cells

Question 26

IL-6 is primarily involved in the induction of the _____

Answer 26

acute phase response

Question 27

IL-6 acts on ____ to induce synthesis of acute phase proteins such as ____ and ____ that bind to bacteria and act as opsonins

Answer 27

hepatocytes; CRP (C-reactive protein); MBP (mannose binding protein)

Question 28

CRP and MBP activate the _____

Answer 28

complement cascade

Question 29

TNF-alpha induces these cytokines, stimulating the immune response and affecting the brain, and leading to sickness behavior

Answer 29

IL-1 and IL-6

Question 30

Primary mediator of innate immune response to intracellular pathogens

Answer 30

IL-12

Question 31

IL-12 is important for the generation of ____ immune response that would be appropriate for intracellular pathogens, i.e. ______

Answer 31

adaptive; T helper cell type 1 (Th1) immunity

Question 32

IL-12 induces the production of ____, which is what ACTUALLY activates _____

Answer 32

IFN-gamma; macrophages

Question 33

IFN-gamma can be produced by:

Answer 33

NK cells, T helper cells, and cytotoxic T cells

Question 34

____ is what causes macrophages to kill a phagocytosed pathogen

Answer 34

IFN-gamma

Question 35

cytokines involved with Th1 type immunity

Answer 35

IFN-gamma (and IL-2)

Question 36

cytokines involved with Th2 type immunity

Answer 36

IL-4, 5, and 13 (and IL-2)

Question 37

needed for growth, survival, and differentiation of T cells (needed for BOTH T helper cells and cytotoxic T cells).

Answer 37

IL-2

Question 38

____ is IL-2 dependent

Answer 38

clonal expansion

Question 39

IL-2 is produced by ____

Answer 39

T helper cells (CD4+ T cells)

Question 40

adaptive immunity most effective against intracellular pathogen

Answer 40

Th1 immunity

Question 41

Th1 immunity involves ____, ____, and _____

Answer 41

macrophages; cytotoxic T cells; IFN-gamma (also IL-2)

Question 42

adaptive immunity most effective against extracellular pathogens (parasites)

Answer 42

Th2 immunity

Question 43

Th2 immunity involves antibodies produced by ____, ____, and _____

Answer 43

B cells; mast cells; eosinophils

Question 44

Th2 immunity involves ___, ___, and ____

Answer 44

IL-4, IL-5, IL-13 (and IL-2)

Question 45

____ drives Th2 immune response and is also a produce of Th2 immunity

Answer 45

IL-4

Question 46

destruction of Th1 immunity causes ____ and destruction of Th2 immunity causes ____

Answer 46

autoimmune diseases; allergies

Question 47

additional functions of IFN-gamma

Answer 47

- enhance microbicidal activity - increase production of opsonizing antibodies - increase Ag presentation so cytotoxic T cells can kill intracellular pathogens

Question 48

can induce naïve Th cells to differentiate into Th2 cells (i.e., Th cells that will produce more IL-4 or IL-13 or IL-5)

Answer 48

IL-4

Question 49

IL-4 is primary stimulus for Ig class switching to ____

Answer 49

IgE

Question 50

Very similar to IL-4 (both functionally and structurally). | Primary job is to help induce Ig isotype switching to IgE.

Answer 50

IL-13

Question 51

IL-13 can stimulate mucous production in ___ and ____; can facilitate inflammation by increasing ____ and ____ expression

Answer 51

gut; lung; adhesion molecules (selectins or integrins); chemokine

Question 52

IgE is a trigger for _____

Answer 52

mast cell degranulation

Question 53

if IL-4 or IL-13 is present, B cells start to make ____; if IFN-gamma is present, B cells start to make ___

Answer 53

IgE; IgG

Question 54

5 receptor families for cytokines and chemokines

Answer 54

1. type I cytokine receptor 2. type II cytokine receptor 3. TNF receptor family 4. IL-1 receptor family 5. 7 transmembrane GPCRs

Question 55

type I cytokine receptors signal via ____ cascades

Answer 55

Jak-STAT

Question 56

type II cytokine receptors are receptors for ____ and ____

Answer 56

IFN-gamma; IL-10

Question 57

difference between type I and type II cytokine receptors

Answer 57

same intracellular signaling cascade (Jak-STAT); different extracellular cytokine binding domain

Question 58

TNF receptor can induce multiple signaling cascades; can lead to ____ or ____

Answer 58

transcription factor expression; apoptosis

Question 59

____ is a major transcription factor in the immune system that can be activated by TNF receptor (induces inflammatory cytokines)

Answer 59

NFkB

Question 60

IL-1 receptor signaling has many similarities to the ____

Answer 60

toll-like receptors

Question 61

IL-1 receptor family has conserved cytosolic sequence, called the _____ domain that activates _____ (initiates signaling cascade)

Answer 61

toll-like/IL-1 receptor (Tir); IRAK

Question 62

7 transmembrane GPCRs are all the ____ receptors; ___ and ____ signaling cascade

Answer 62

chemokine; rapid and transient

Question 63

____ and ____ are 2 of the biggest transcription factors in the immune system

Answer 63

NFKB; STAT