Cytokines

Question 1

Major effects of Type 1 interferons.

Answer 1

Reduce viral replication and build defense against viruses. Commonly used in broad-spectrum antivirals. Treatments for Hep B, Hep C and MS.

Question 2

What are Jak/Stat proteins? Provide an example of a cytokine that uses these molecules.

Answer 2

Jak/Stat molecules play a role in signal transduction for a cell being affected by a cytokine. One example is IL-2 which is involved in the growth/division of T-cells.

Question 3

List at least 3 ways chemokines differ from cytokines.

Answer 3

Chemokines are smaller molecular agents, signal through GPCRs and are chemotactic. The latter term means they attract inflammatory/effector cells and play a role in developmental targeting of cells to organs.

Question 4

Describe the function and feature of Interleukin-1.

Answer 4

IL-1 is involved in inflammation and is an an endogenous pyroxene (stimulates fever). It works together with IFN-gamma.

Question 5

List 3 ways cytokines differ from chemokines (in size, function and receptor usage).

Answer 5

1. LARGER soluble proteins.
2. Protein kinase-coupled receptors.
3. stimulate growth, differentiation and defensive capacity of immune system cells.

Question 6

Define the following terms in regards to cytokines.

1. Pleiotrophy

2. Redundancy

Answer 6

1. One cytokine has different effects on many cell types.

2. Different cytokines can have the same or overlapping effects.

Question 7

What is a major transcription factor in the pathway of pro-inflammatory cytokines.

Answer 7

IL-1, TNF-alpha and IL-6 are the pro-inflammatory cytokines. NF(kappa)-B is a latent transcription factor involved in activation of inflammatory genes.

Question 8

What cytokine is produced by Th1 cells? Describe its function.

Answer 8

IFN-gamma is made by Th1 helper cells. It is responsible for macrophage activation.

Question 9

What cytokines are produced by Th2 cells? Describe their functions.

Answer 9

IL-4, IL-5 and IL-13 are made by Th2 cells. These are responsible for allergies and mast-cell activation.

Question 10

How does IL-10’s action differ from that of IL-1, TNF and Type 1 IFNs?

Answer 10

IL-10 is an anti-inflammatory cytokine. It is secreted by Th2 cells and binds Type 2 Cytokine receptors to inhibit monocytes, neutrophils and cytkine production. This cytokine inhibits Th1 function.

Question 11

Describe 2 major functions of chemokines.

Answer 11

Chemokines signal for chemotaxis and modulate cell adhesion.

Question 12

State the role of CCR5 on HIV infection.

Answer 12

CCR5 is a chemokine receptor found on macrophages and some T-cells. This works together with CD4 (on cells) to permit productive infection.

Question 13

Which interleukin is a prominent chemokine?

Answer 13

IL-8 is a chemokine that functions to recruit inflammatory cells to sites and secondary lymphoid organs.

Question 14

What is the function of Interleukin-17? Where does it come from?

Answer 14

IL-17, produced by T-lymphocytes, (Th17) functions to recruit neutrophils and monocytes.

Question 15

A mutation in the gamma-c component of Interleukin 4/5 results in what disease?

Answer 15

X-linked severe combined immunodeficiency (SCID) can occur that presents as decreased T-cells and NK cells. B-cell count is not affected.

Question 16

What cytokines contribute to the following symptoms at high levels?
high fever, low BP, high RBC-sedimentation rate (ESR)

Answer 16

TNF-alpha or IL-1 (endogenous pyroxene) play a role in systemic inflammation

Question 17

What disease is the preferred method for a diagnosis a test for pathogen-specific cell-mediated immune response?

Answer 17

Tuberculosis infection.

Question 18

For what disease is the preferred method for diagnosis a test for pathogen-specific antibodies?

Answer 18

Lyme disease (Borrelia burgdorferi)

Question 19

What component of the Gram-negative bacteria is most effective in producing a patient’s fever?

Answer 19

Lipopolysaccharide (LPS).

Question 20

What cytokines are known to cause fever like symptoms in an inflammatory reaction?

Answer 20

IL-1 and TNF-alpha are both endogenous pyroxenes that stimulate fever-like temperatures.

Question 21

Interleukin-6 inhibits _______; whereas interleukin-10 inhibits ________.

Answer 21

IL-6 inhibits TNF-alpha and IL-1 action by macrophages;

IL-10 from Th2 cells inhibits monocyte and neutrophil cytokine production (as well as TH1 secretions).

Question 22

Lack of IFN-gamma puts a patient at risk of developing what primary immunodeficiency syndrome?

Answer 22

Chronic Granulomatous Disease (CGD) that features decreased function of neutrophils and macrophage killing capacity.

Question 23

What cytokine can be used as a therapeutic agent for broad-spectrum antivirals (treatments for Hep. B, Hep C, and MS)?

Answer 23

IFN-alpha and beta (type 1 interferons) are anti-viral cytokines, released from NK cells and TH1 cells.

Question 24

A drug that modulates the stimulation of G-protein coupled cascade should ideally work to inhibit the function of what regulatory enzyme?

Answer 24

Phosphodiesterase. This enzyme converts cAMP to AMP to offset the activation of adenylate cyclase by GPCR.

Question 25

The development of polyclonal hypergammaglobulinemia would result from increased levels of what 2 cytokines? Why?

Answer 25

IL-4 and IL-10 is secreted by Th2 that responds to this immunodeficiency that would help B cells make antibodies.