Cytokines (class 1)

Question 1

What are Cytokines?

Answer 1

“Small soluble proteins that regulate the immune system’s innate and adaptive responses to infection
- communication molecules “

Question 2

How are Cytokines induced?

Answer 2

Induced in response to specific stimuli

Stimuli - bacterial lipopolysaccharides, flagellin, other products; signaling through Tcell/Bcell receptors

Question 3

How are Cytokines produced?

Answer 3

Occurs through the ligation of cell adhesion molecules or through the recogniction of foreign antigens/molecular patterns by host lymphocytes

Question 4

Cytokine function and effects

Answer 4

• the communication molecules of the immune system
• Individual cytokines often act in concert with others -> cytokine concert/network -> regulation of leukocyte activity
  Effects-in vivo- growth regulation and gene expression but many different cell types (includes leukocytes)

Question 5

Autocrine stimulation of Cytokines

Answer 5

Affects are seen on the same cell that secreted it

Question 6

Paracrine stimulation of Cytokines

Answer 6

Affects cells in close proximity

Question 7

Endocrine stimulation of cytokines

Answer 7

AKA systemic; moved by the endocrine system

Question 8

The major cytokine families

Answer 8

Tumor necrosis factor (TNF) 
Interferons (IFN) 
Chemokines 
Transforming Growth Factors (TGF) 
Colony-Stimulating Factors (CSF)

Question 9

IL-3, erythropoietin (EPO) and granulocyte (G-CSF),
macrophage (M-CSF), and granulocyte-macrophage (GM-CSF) are all types of what?
What is their function?

Answer 9

Colony stimulating factors
- in response to inflammatory cytokines, the different CSF act on bone marrow cells and promote specific colony formation for the various cell lineages

Question 10

What is the difference between cytokine related IL and unrelated IL

Answer 10

Unrelated-satisfy 3 criteria (genes were cloned, inducible in Leukocytes, biological activites in inflammatory processes must be cataloged

Question 11

Cytokine pleiotropism

Answer 11

The cytokine has different affects on different cell types

[one cytokine -> multiple functions]

Question 12

Cytokine redundancy

Answer 12

Overlapping effects of cytokines, because many share receptors –> altering of activity of the same genes
[multiple cytokines –> same function]

Question 13

Cytokine synergy

Answer 13

Cytokines that work together –> amplified/different effects than individual cytokines
- multiple cytokines working together

Question 14

Cytokine antagonism

Answer 14

A cytokine counteracts the effects of other cytokines

- one cytokine opposes the function of another

Question 15

What are the cytokines of the innate immune system?

Answer 15

Type 1 interferons (alpha/beta) 
Tumor necrosis factor alpha 
interleukin 1 beta 
Interleukin 10 
Transforming growth factor beta 
[Chemokines, IL-8, Fractalkine, RANTES, SDF-1alpha]
(INF1a/B, TNFa,IL1B,IL10,TGFB)

Question 16

What interferons interfere with viral replication

Answer 16

“*was once named for function of viral replication interferance then found other interferons that have other functions
- Now know its just type 1 interferons (alpha/beta) “

Question 17

What is the function of Type 1 IFN?

Answer 17

Produce virally infected cells and by dendritic cells and induce production of proteins and pathways that can directly interfere with viral replication and cell division

• Activates NK cells and enhances expression of MHC class 1 proteins
• Also active against certain malignancies and other inflammatory processes

Question 18

How are cytokines involved with the innate immune response?

Answer 18

Responsible for many physical symptoms

inflammation, fever, swelling, pain, cellular infiltrates into damaged tissues

Question 19

What is the main function of the innate immune response and how do cytokines help?

Answer 19

To recruit effector cells to this area

TNF alpha, IL-1, chemokines and INF alpha and beta

Question 20

TNF - alpha importance and function

Answer 20

Most prominent member of the TNF superfamily, which consists of at least 19 different biological functions

• secreted by activated monocytes and macrophages can T cells through its ability to induce expression of the MHC class 2 molecules, vascular adhesion molecules, costimulatory molecules (CD80/86, B7.1/B7.2) and chemokines exhists in both membrane -bound soluble forms and causes vasodilation and increased vasopermiability
• triggered by lipopolysaccharide, found in gram-negative bacteria

Question 21

Describe the IL-1 family

Answer 21

Consists of the IL-1a, IL-1B and IL-IRA (receptor antagonist)

• Acts as an endogenous pyrogen and induces fever in the acute phase response through its actions on the hypothalamus
• induces the production of vascular cell-adhesion

Question 22

How does IL- 1 alpha/beta differ from other IL - 1 family

Answer 22

IL-1a/b - proinflammatory cytokines produced by monocytes and Macs
IL-1B - responsible for most of the systemic activity attributed to IL-1, including fever, activation of phagocytes and production of acute phase proteins

Question 23

How are cytokines involved in chronic inflammation?

Answer 23

TNF a and IL-1 - in rheumatoid synovial fluids and synovial membranes of patient w/ rheumatoid arthritis
TNF a - central mediator of pathological processes in RA and other inflammatory illnesses (ex Crohn’s disease)
Sepsis - see high levels of proinflammatory cytokines in the blood
Increased inflammatory cytokines seen in chronic HIV disease, atherosclerosis, psoriasis, binge drinking

Question 24

What are chemokines?

Answer 24

Direct immune cells to places of interest
- Family of cytokines that enhance motility and promote migration of many types of WBCs toward the source of the chemokine