Cytokines

Question 1

what are cytokines

Answer 1

simply: cytokines are involved in cell communication!

Cytokines :
* Small proteins/glycoproteins
* Act via specific receptors
* Some called interleukins (IL) - IL-1 to IL-37
* Inter- since communication between cells
* Others not - e.g. Tumour necrosis factor a (TNFa) or interferon gamma (INF-gamma)
* 2 cytokines found evolutionary back in sea urchins (homologues)
* TNFa
* IL-17 (repair cytokines)
Include subfamily involved particularly in cell movement (chemotaxis) - chemokines

Cytokines are small glycoproteins that are crucial in controlling the growth and activity of other immune cells. When released, they signal the immune system to do its job. Cytokines affect the growth of all blood cells and other cells that help the body’s immune and inflammation responses

Question 2

what are chemokines

Answer 2

Chemokines (a subfamily of cytokines):
* Small polypeptides - 90-130 aa
* chemokines allow cell-cell communication in chemotaxis
* Signal through GPCRs (G-protein coupled receptors
* Receptors can bind multiple chemokines
* WBCs differentially express chemokine receptors
*Control adhesion, chemotaxis, activation

Question 3

which cytokine is involved in toxic shock syndrome?

Answer 3

TSS are mediated by exotoxins which activate the immune system to release inflammatory cytokines. These exotoxins act as superantigens, causing T cell activation and the resulting “cytokine storm” (TNF-alpha, interleukin [IL]-1, and IL-6) leads to profound shock and multi-organ failure.

Question 4

the following are attributes of cytokines; define these

• Pleiotropy
• Redundancy
• Synergy
• Antagonism
• Autocrine
• Paracrine
• Endocrine

Answer 4

• Pleiotropy - cytokine can exert multiple effects
• Redundancy - different cytokines can do same job
• Synergy - cytokines act together to cause an effect
• Antagonism - cytokines also have opposing effects
• Autocrine - same cell secreting them is target
• Paracrine - nearby cell is target
• Endocrine - distant cell is target

Question 5

which of these are inflammatory cytokines vs. anti-inflammatory cytokines?
*IL-1
*TNF-alpha
*IL-6
*IL-10
*TGF-beta

Answer 5

inflammatory: IL-1,TNF-alpha,IL-6

anti-inflammatory: IL-10,TGF-beta

Question 6

people with mutation in which cytokine receptor gene develop gut inflammation such as ulcerative collitis?

Answer 6

ppl with mutation in IL-10 receptor genes develop severe gut inflammation ealy in life

these ppl will require a bone marrow transplant

Question 7

which cytokine drive T cell proliferation?

Answer 7

IL-2 drives T cell proliferation

IL-2 is critical in development of T regulator cells (Tregs) in the thymus + the regulation, proliferation + maintenance of Tregs in peripheral tissues

Question 8

Helper T cells make many cytokines that affect other cells
E.g. Th1 cells produce IFN-gamma which activates ________ to kill intracellular bacteria

Answer 8

Helper T cells make many cytokines that affect other cells
E.g. Th1 cells produce IFN-gamma which activates macrophages to kill intracellular bacteria like mycobacterium tuberculosis

n.b. with non-functional IFN-gamma receptors are highly susceptible to mycobacterial infections (like tuberculosis)