Cytokines

Question 1

Cytokines

Answer 1

cells of the immune system that produce hundreds of proteins that control the immune responses.- how cells communicate with each other

Question 2

What happens when cytokines bind to receptors on target cells?

Answer 2

they affect cell behavior. They induce target cell to

1. divide or stop dividing
2. produce other signaling molecules or express new receptors
3. die/commit suicide

Question 3

Characteristics of Cytokines

Answer 3

short lived proteins
highly diverse structures and receptors
toxic in high doses
two principal producers are T helper cells and macrophages

Question 4

Local Functional Features of Cytokines

Answer 4

autocrine, paracrine, endocrine

Question 5

Autocrine

Answer 5

bind to receptors on cell that produces them

Question 6

Paracrine

Answer 6

may bind only to receptors in nearby cells

Question 7

Endocrine

Answer 7

other cytokines may spread throughout the body affecting target cells in distant location

Question 8

Interactive Functional Features of Cytokines

Answer 8

pleiotropic, redundant, synergistic, antagonistic

Question 9

Pleiotropic

Answer 9

Multiple functions

Question 10

Redundant

Answer 10

same function

Question 11

Synergistic

Answer 11

activate or deactivate cells

Question 12

Antagonistic

Answer 12

inhibit effect of other cytokines

Question 13

Cytokine Groups

Answer 13

hematopoietic family
interleukins
interferon family
tumor necrosis factor family
growth factors
chemokine family

Question 14

Interleukins

Answer 14

cytokines that signal between lymphocytes and other leukocytes. They are numbered sequentially in the order of their discovery

Question 15

Interferons

Answer 15

family of cytokines produced in response to virus infection or immune stimulation. Interfere with viral RNA and protein synthesis (antiviral activity)

Question 16

Types of Interferon

Answer 16

Type I, Type II, Type III

Question 17

Type I interferons

Answer 17

IFN-alpha and IFN beta most important. Primarily antiviral with a secondary immunoregulatory role

Question 18

Type II interferon

Answer 18

IFN-gamma. Only one identified.

Question 19

Type III Interferon

Answer 19

IFN- delta. Three have been identified.

Question 20

Tumor Necrosis Factors

Answer 20

Cytokines produced by macrophages and T cells. They can kill tumor cells. TNF-alpha is a key mediator of acute inflammation

Question 21

Growth Factors

Answer 21

aka colony-stimulating factors. control cell production by regulating stem cell activities. Ensure the body is supplied with sufficient cells to defend itself.

Question 22

Chemokines

Answer 22

family of at least 50 small proteins that play a role in leukocyte chemotaxis, circulation, migration, and activation, especially in inflammation. A typical example of a chemokine is CXCL8 (aka IL-8)

Question 23

IL-8

Answer 23

stimulates leukocytes to leave blood stream to site of infection

Question 24

Signal Transduction

Answer 24

ligand binding activates a tyrosine kinase. These activate transcription factors. Gene transcription generates new proteins and affects cell behavior

Question 25

Toll-Like Receptor Signaling

Answer 25

innate immune system. Activated Myeloid differentiation factor 88 (MyD88). Activates the transcription factor NF-kB

Question 26

T Cell Antigen-Receptor Signaling

Answer 26

Adaptive immune system. Activates multiple transcription factors including NF-kB, NF-AT, and AP-1. Causes cell division or apoptosis and cytokine synthesis

Question 27

B Cell Antigen-Receptor Signaling

Answer 27

Adaptive immune system. Activates NF-kB and NF-AT. Triggers cell division or apoptosis and antibody synthesis

Question 28

Major Proinflammatory Cytokines

Answer 28

1. Tumor necrosis factor alpha. 2. Interleukin-1 3. Interleukin-6 4. Multiple chemokines

Question 29

TNF-alpha

Answer 29

produced by macrophages, monocytes, T cells, and mast cells. 1. activates cells 2. toxic effects 3. enhances fibroblast growth, collagen synthesis, and bone resorption 4. promotes inflammation

Question 30

IL-1

Answer 30

Produced by macrophages and many others 1. affects metabolism 2. affects blood flow 3. affects cell growth 4. affects the brain 5. kills cells 6. affects leukocytes 7. promotes inflammation

Question 31

IL-6

Answer 31

Produced by macrophages, T and B cells, dendritic cells, basophils, eosinophils, fibroblasts, keratinocytes, myocytes. 1. activates B cells 2. enhances IgA production 3. Causes fever 4. acute-phase response of hepatocytes 5. Stimulates Th2 responses 6. Activates Th17 cells 7. Suppresses Treg cells 8. enhances cytotoxicity

Question 32

Chemokines

Answer 32

small proinflammatory cytokines. powerful chemoattractants for cells. The chemokine mixture generated determines the mixture of cells that converge on the site. At least 50 different chemokines and an equal variety of receptors. Interleukin-8 is the prototypical chemokine

Question 33

Regulation of Cytokine Activity

Answer 33

1. Receptor blockage by inert ligands such as IL-1 receptor antagonist. 2.Provision of soluble decoy receptors. 3. counteracting cytokines

Question 34

Network Transmission

Answer 34

when 2 cells come into direct contact using complementary receptors. Signals are then transmitted directly through these two receptors

Question 35

What cytokines are involved in a cytokine storm?

Answer 35

IL-1beta, IL-6, IL-17, IL-18, TND, interferon gamma, MIP 1 alpha and 1 beta.