Lecture 3 - Cytokines

Question 1

Describe cytokines.

Answer 1

They are signaling proteins or proteins made by certain cells as a mechanism to communicate with other cells.

Question 2

What are chemokines?

Answer 2

A type of cytokine that is more specialized in their function of attracting and guiding leukocytes

Question 3

Cytokines bind to surface receptors called ____________ which are found on the cells cytokines regulate.

Answer 3

cytokine receptors

Question 4

What are 3 ways cytokines can act in?

Answer 4

Autocrine (same cell), paracrine (close proximity), & endocrine (long distance)

Question 5

What are the cytokine families? (4)

Answer 5

Hematopoietic family
Interferon family
Tumor necrosis factor family
Chemokine family

Question 6

Which of the cytokines families elicit physiological responses and which elicit chemoattractant?

Answer 6

Physiological responses: Hematopoietic family, interferon family & tumor necrosis factor family
Chemoattractant: Chemokine family

Question 7

Some defense cells have ________ receptors and can migrate to the site of recruitment e.g. ________ migrate to an area of inflammation.

Answer 7

chemokine; neutrophils

Question 8

What does CSF stand for and their importance?

Answer 8

Colony stimulating factors; important in the multiplication & differentiation of leukocytes

Question 9

What happens during an immune response and when more leukocytes are needed?

Answer 9

Various colony stimulating factors direct immature cells into the appropriate maturation pathways.

Question 10

What are the different types of cytokines?

Answer 10

Chemokines, colony stimulating factors (CSF), interferons (INFs) interleukins (ILs), & tumor necrosis factors (TNFs), pro-inflammatory

Question 11

What does INF stand for? And list 3 things about it.

Answer 11

Interferons; important in the control of viral infections, help regulate functions of the cell involved in inflammatory response, moderate some responses of the adaptive immune sys.

Question 12

What does IL stand for and 3 things about it.

Answer 12

Interleukins; produced by leukocytes (white blood cells), important for both innate and adaptive immunity (inflammatory response), activities overlap with CSFs…creates redundancy

Question 13

What does TNF stand for, and 2 things about them.

Answer 13

Tumor necrosis factors; TNFα plays an important role in initiating the inflammatory response, can initiate apoptosis or programmed cell death

Question 14

Groups of cytokines often act together to facilitate what? Give an example.

Answer 14

A particular response by the host defenses; Pro-inflammatory cytokines (TNF-α, IL-1, IL-6) contribute to inflammation

Question 15

We cannot have an immune response in the body without what?

Answer 15

Cytokines

Question 16

State effects of chemokines.

Answer 16

chemotaxis

Question 17

State the effects of colony-stimulating factors (CSFs).

Answer 17

Stimulation of growth and differentiation of dif. kinds of leukocytes

Question 18

State the effects of interferon alpha.

Answer 18

Antiviral…induces fever, contributes to inflammation

Question 19

State the effects of interferon beta.

Answer 19

Antiviral…induces fever, contributes to inflammation

Question 20

State the effects of interferon gamma.

Answer 20

Antiviral…macrophage activation, development & regulation of adaptive immune response

Question 21

State the effects of interleukins-1.

Answer 21

Proliferation of lymphocytes, macrophage product of cytokines, induce fever

Question 22

State the effects of IL-2 (T-cell growth factor).

Answer 22

Changes in growth of lymphocytes, activation of natural killer cells, promote adaptive cell-mediated immune response.

Question 23

State the effects of IL-3.

Answer 23

Changes in growth of precursors of blood cells & also mast cells

Question 24

State the effects of IL-4, IL-5, IL-10, IL-14.

Answer 24

Promote antibody responses

Question 25

State the effects of tumor necrosis factor (TNF) alpha.

Answer 25

Initiate inflammatory response, cytotoxicity for some tumor cells, regulate certain immune functions, induce fever

Question 26

State the effects of tumor necrosis factor (TNF) beta.

Answer 26

Killing of target cells by cytotoxic T cells and natural killer cells

Question 27

What are the 4 highly interactive features of cytokines? And their importance.

Answer 27

Pleiotropic, redundant, synergistic, antagonistic; these functional features play important roles in maintaining cellular homeostasis and regulating various biological processes.

Question 28

Describe the structure of cytokine receptors.

Answer 28

Have the surface component, single transmembrane component, & cytoplasmic tails.

Question 29

What are adhesion molecules?

Answer 29

They are surface level proteins (CAMs) that bind cells w/ other cells or extracellular matrix

Question 30

What are 4 types of CAMs that are used to hold animal cells together?
All are _________________ proteins anchored to the ______ by their cytoplasmic domains.

Answer 30

Cadherins, Ig-like CAMs, selectins, integrins; single-pass transmembrane; cytoskeleton

Question 31

Describe the JAK/STAT pathway.

Answer 31

STAT attaches to JAK with cytokine mediators…releases signals to activation transcription…changes DNA to RNA

Question 32

Explain pleiotropy in more detail.

Answer 32

Pleiotropy refers to a protein or cytokine having the ability to activate multiple signaling pathways

Question 33

Explain redundancy in more detail.

Answer 33

Redundancy occurs when multiple proteins have overlapping functions, providing a backup mechanism.

Question 34

Explain synergy in more detail.

Answer 34

2 different cytokines have a greater effect in combination than either of the two would by themselves

Question 35

Explain antagonism in more detail.

Answer 35

Oppostie of synergy; the effect of 1 protein counteracts/inhibits the effects of another protein.