Cytokines and chemokines

Question 1

Define cytokines

Answer 1

Small soluable proteins thay are secreted by cells which have an influence on other cells which have receptors for them ,sometimes also called interleukins i.e. factors acting between white blood cells)

Question 2

List the 3 ways in which cytokines can act

Answer 2

1. Autocrine signaling : When a cell talk to itself
2. Paracrine signaling : when a cell talks to other cells in the immediate environment
3. When a substance is secreted into the environment to communicate with distant sites

Question 3

How can cytokines be classified

Answer 3

1. By structure or family
2. By function

Remember that not cytokines are secreted. Some are actually attached to cells but still have an immunological function

Question 4

T/F . Cytokines of similar families have similar functions

Answer 4

true

Question 5

How are cytokine functions classified?

Answer 5

1.Growth factors : Stimulate proliferation and replication of immune cells

2.Proinflammatory cytokines
3.Th1 : activates immune system against pathogens
4Th2 cytokines: Activates B cells
5. Regulatory cytokines_ stops the immune cells

Question 6

List the cytokines involved in inflammation

Answer 6

1. TNF-alpha
2. IL-1
3. IL-6

they are responsible for sickness behavior and chemotaxis and inflammatory response. They are increased in patients with chronic inflammation

Question 7

list the example and functions of growth factor cytokines

Answer 7

IL2: T cell proliferation
IL-4: Stimulates B cell proliferation 
 IL7: Stimulates B cell maturation 
IL-7; Assists VDJ recombination
Il 15; Stimulates NK cell proliferation

Question 8

Give example and function of T helper 1 cytokines

Answer 8

IL 12
Interferon gamma
they activate cytotoxin t cells to kill virally infected cells

Question 9

Give function and example of T helper 2 cytokines

Answer 9

IL4(growth factor)
IL5
IL 13

They help B call to proliferate , mature and undergo class switching

Question 10

Give example and function of anti-inflammatory cytokines

Answer 10

IL10 
TGF beta ( transforming Growth beta)

Question 11

List the types of interferons

Answer 11

type 1 : are alpha and beta
type 2 ; gamma

they are all Th1 cytokines thus they are effective against intracellular pathogens

Question 12

discuss the type 1 interferons

Answer 12

They are alpha and beta

They are antiviral cytokines

They are secreted by virally infected cells as well as immune cells

they are a cal for help to the CD8 cells(cytotoxic T cells ) and NKC

their functions is to :
Cause upregulation of MHC 1 proteins

Activate NKC and they activate antiviral defenses in the cell

Question 13

Discuss the function of interferon gamma

Answer 13

they promote maturation of professional APC

Upregulation of both MHC 1 and 2

Promotes switching from IgM to IgG

suppress the Th2 responses

Question 14

Function of the Tumor necrosis factor family

Answer 14

1. Initially linked with cell death and cachexia ( wasting way due to not eating ) .It often contains death domains especially TNF aloha and fas ligand and trail they are responsible for inflammation :
2. Increase vascular permeability
3. Leukocyte recruitment
4. Sickness behavior

Question 15

what is the function of interleukin 10

Answer 15

It is an antiinflammatory cytokine ;it reduces inflammation by preventing APC maturation and inhibiting macrophage function

IL 10 secretion is stimulated

• At the end of the inflammatory process
• By high dose steroids’
• By bugs and tumors trying to evade the immune systems

Question 16

What is the function of transforming growth factor beta

Answer 16

It is associated with conversion of normal cells to malignant cells

TGF- beta is associiated with; healing

• Recruitment of fibroblasts and smooth muscles
• Scaring
• Angiogenesis
• Inhibition of macrophages ,b cells and T cell activation

Question 17

What is the function of NKC

Answer 17

Promotes CD8 upregulation and differentiation

Plays an important role in NKC

can also be regarded as Th1 cytokine

Question 18

What is the function of LI17

Answer 18

Secreted by Th17 cells
Develop under the influence of LI13(which plays a role in B cells maturation)

Strongly pro-inflammatory -it is associated with many autoimmune diseases

Question 19

How does cytokines affect naïve T cells

Answer 19

The cytokines environment will target the T cell towards the correct response

Question 20

How do we switch off cytokines

Answer 20

1.Cytokines signaling is suppressed by suppressors of cytokines signaling(SOCS)

SOCS production is stimulated by the pathway

Question 21

What are the functions of chemokines

Answer 21

chemical massagers’ that induces the movement of cells down their concentration gradient they are secreted homeostatically and also as a part of an inflammatory response

Question 22

What is the function of CXC chemokines

Answer 22

They attract leukocytes (neutrophils and lymphocytes)

they cause coagulation as well

Question 23

What is the function of CC chemokines

Answer 23

they are the most common chemokines

and they attract mononuclear cells ie monocytes and lymphocytes

Question 24

How are cytokines applied or used in clinical settings

Answer 24

1. Cytokines are manipulated to change disease putcomes
2. Cytokines are used to ttreat cancer
3. Cytokines are blocked to prevent autoimmune dieases