IMSE311_Week 5: Cytokines

Cytokines

Chemical messengers that regulate the immune system.

Pleiotropy

Property of cytokines meaning “having many different effects.”

Redundancy

Feature where two cytokines share the same receptor.

Synergy

Cooperative effect of multiple cytokines

Antagonist

Inhibition of one cytokines effects by another cytokine

Receptor Antagonist

Cytokines that tends to stop the activity of a particular cytokines, If the cytokines is no longer needed.

Cytokine Storm

Massive uncontrolled overproduction of cytokines.

Autocrine

Cytokine action affecting the same cell that secreted it.

Paracrine

Cytokine action affecting nearby cells.

Endocrine

Cytokine action that produces systemic effects.

TNF-Tumor Necrosis Factor

Principal mediator of acute inflammatory response to gram-negative bacteria.

TNF-a

• other term Cachectin

• Found in tumor cells, it induced lysis in these cells

• Most prominent member of the TNF family

• secreted by activated monocytes and macrophage

Interleukin 6

• produce by lymphoid and non lymphoid cell types

Chemokines

• enhance motility and promote migration of many types of WBC

IL-2

Cytokine known as T-cell growth factor.

IFN-α and IFN-β

Cytokine that interferes with viral replication.

Th1 Cytokines

• Produce by dendritic cells in damaged tissues produce IL-12.

• response to certain stimuli such as mycobacteria, intracellular bacteria and viruses.

Erythropoietin (EPO)

Cytokine responsible for RBC production.

Thrombopoietin (TPO)

Cytokine mainly involved in platelet production.

Chemokines

Cytokine that enhances chemotaxis of WBCs.

IL-1RA

Cytokine that limits IL-1 activity.

IL-4

Cytokine responsible for allergic reactions and parasitic infections.

Interleukin 1

• Associated with inflammation

• Mediator of the innate immune response

IL- 1A and IL-1B

Pro-inflammatory cytokines produce by monocytes and macrophage

IL-1 (Receptor Antagonist)

• limits the availability of IL-1, turn off the response when no longer needed

• Produce by monocytes and macrophage.

False

Cytokines act independently and do not influence other cytokines.

True

IL-1 is associated with inflammation.

True

TNF-α can cause vasodilation and increased vascular permeability.

True

IL-6 is involved in acute phase reactions.

False

IFN-γ is produced mainly by Th2 cells

True

IL-10 inhibits pro-inflammatory cytokines.

True

IL-2 promotes growth of T-cytotoxic cells.

True

TGF-β suppresses immune response.

False

IL-4 and IL-10 have exactly the same immune effects.

Types of Interleukin 1 or IL-1

1. IL-1A

2. IL-1B

3. IL-1RA

Types of cells that can produce IL-6

• T-cells

• B-cells

• Monocytes and macrophage

• Fibroblasts

• Hepatocytes

• keratinocytes

• Astrocytes

• Endothelial cells

• Some tumor cells

Pleomorphic activities of IL-6

• inflammation

• Acute phase reaction

• Immunoglobulins synthesis

• Activation states of B-cells and T-cells

• Proliferation and Differentiation of B-cells into Plasma cells

Chemokines Classified into 4 families

1. Alpha or CXC chemokine

2. Beta or CC, chemokines

3. C Chemokines

4. CX3C

Subclasses of CD4+ T cells or T helper

1. Th1/ T helper type 1

2. Th2/ T helper type 2

3. T-reg/ T regulatory

Enumerate the Different Families of Cytokines:

1. Tumor Necrosis Factors (TNF)

2. Interferons (IFN)

3. Chemokines

4. Transforming Growth Factors (TGF)

5. Colony Stimulating Factors (CSF)

6. Interleukins (IL)

Enumerate the Features of Cytokines:

1. Pleiotropy

2. Redundancy

3. Synergy

4. Antagonism

5. Act in Networks

6. Act as Growth Factors

Enumerate Th1 Cytokines:

• IL-2

• IFN-γ

Enumerate Th2 Cytokines:

• IL-4

• IL-5

• IL-10

• IL-13

Enumerate Cytokines Involved in Innate Immune Response:

1. IL-1

2. TNF-α

3. IL-6

4. Chemokines

5. TGF-β

6. IFN-α

7. IFN-β