Cytokines, Chemokines and their receptors Flashcards Preview

Micro FINAL EXAM > Cytokines, Chemokines and their receptors > Flashcards

Flashcards in Cytokines, Chemokines and their receptors Deck (48)
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1
Q

What is a cytokine?

A

Proteins secreted by cells that mediate the functions of the immune system.

2
Q

What are the cellular sources of cytokines?

A
  • lymphocytes
  • monocytes
  • all cells of innate immune system
  • all cells of adaptive immunity
  • other cells….
3
Q

What is a interleukin (Cytokine)?

A

Term refers to fact that many proteins are produced by one immune cell to act on neighboring cells. (They work between cells)

4
Q

What are the 6 general properties of Cytokines?

A
  1. Cytokine secretion is brief and self limited.
  2. Cytokine action is pleiotropic and redundant.
  3. Cytokines influence each other.
  4. Cytokine initiate their actions by binding to specific membrane-bound receptors.
  5. Cytokines can act locally or systemically.
  6. Cytokine receptor liagtion leads to gene expression which alters Cellular function.
5
Q

True or false, Cytokines can be antagonistic to each other?

A

True

6
Q

Cytokines can act in ________.

A

Synergy

7
Q

What are chemokines associated with?

A

Inflammation

8
Q

_____ stimulates the production of IFN-Gamma.

A

IL-12

9
Q

What are the two main types of Cytokines involved in innate immunity?

A
  • Proinflammatory = TNF-alpha (Main one)

- Antiinflammatory = IL-10 & TGF-B

10
Q

What are the main producers of TNF-aplha?

A

Monocytes, macrophages, NK cells, and T cells are main ones.

11
Q

What is the important function of TNF-alpha?

A

Stimulates the recruitment of neutrophils, monocytes and activated T-cells to the site of infection.

12
Q

TNF-alpha increases the expression of _____ & then ______.

A

E- Selectin and the P-selectin

13
Q

True or false, TNF-alpha can has only beneficial effects.

A

False, it can also have detrimental effects. High levels result in septic shock, while moderate levels result in fever.

14
Q

Interlukin 1 (IL-1) has what two forms?

A

IL-1 alpha and IL-1 beta

- have same biological function

15
Q

What cells produce IL-1?

A

Primary producers are mononuclear phagocytes and neutrophils.

16
Q

______ shares many of the same effects as TNF-alpha.

A

IL-1

17
Q

What are THE BIG 3 Proinflammatory cytokines?

A

TNF-alpha
IL-1
IL-6

18
Q

What produces IL-6?

A

Macrophages and T cells mostly

19
Q

What is the function of IL-6?

A

Involved with induction of inflammatory response, but PRIMARILY involved with the induction of the acute phase response.

20
Q

What makes you “feel sick” when you are ill?

A

Cytokines (IL-6, TNF-alpha, IL-1( get into brain pathways and help create sickness symptoms such as:
Loss of appetite
being tired
loss of sex drive

21
Q

What is the function of IL-12?

A

Primary mediator of the innate immune response to intracellular pathogens and Important for the generation of immune response that would be appropriate.

22
Q

True or False, IL-12 activates macrophages.

A

FALSE! it does not directly activate macrophages. it does so through t helper cells.

23
Q

____ is a key Th2 cytokine.

A

IL-4

24
Q

What is the function of IL-4?

A

It can induce naive Th sells to differentiate into th2 cells that will produce more IL-4 or IL-13 or IL-5.

25
Q

____ is the primary stimulus for Ig class switching to IgE/

A

IL-4

26
Q

What is the Job of IL-13?

A
  • very similar to IL-4 both structurally and functionally.
  • PRIMARY job is to help induce Ig isotype switching to IgE.
  • *Also stimulates mucous production in gut and lung (unique function)
    • can facilitate inflammation by increasing adhesion molecule and chemokine expression.
27
Q

What is the Job of IL-5?

A

PRIMARY job is in eosinophil differentiation, proliferation and activation.
*Eosinophils are necessary for protection against parasites.

28
Q

______ & _____ are involved in allergic responses.

A

IL-5 & other Th2 cytokines

29
Q

_______ is important for immune response against EXTRAcelluar pathogens.

A

Th2 cytokines (IL-4, IL-13, IL-5)

30
Q

_____ is important for immune response against INTRAcellular pathogens.

A

Th1 (IFN )

31
Q

______ cytokines are often considered inflammatory.

A

Innate cytokines (TNF, IL-1, IL-6)

32
Q

____ & _____ help to acitvate adaptive immune response (Particularly Th1 immune response)

A

IL-12 & IFN

33
Q

IL-10 is a ________ cytokine.

A

Inhibitory

34
Q

What produces IL-10?

A
  • Macrophages
  • dendritic cells
  • T helper cells.
35
Q

What is the function of IL-10?

A

PRIMARY function is to inhibit production of IL-12 by activated macrophages and dendritic cells.

36
Q

What are Chemokines?

A

Essentially they are Chemotactic cytokines.

  • small soluble proteins
  • There are a lot of them (over 50 identified)
  • Chemokines make up the largest category of cytokines.
37
Q

How do chemokines usually work?

A

in paracrine or endocrine manner

38
Q

What is the job of Chemokines?

A

PRIMARY role is to regulate migration of cells to peripheral tissues or to lymph nodes.

39
Q

How are Chemokoines classified?

A

By the # and location of N-terminal cysteine residues.

40
Q

True or False, Chemokine subclass matches Chemokine receptor subclass.

A

TRUE!

  • CC binds to CC receptor
  • CXC binds to CXC receptor…..you get the idea
41
Q

Activated cells follow a ________.

A

Chemokine gradient

42
Q

True or false, All receptors have at least 1 extracellular binding domain and 1 Intracellular signaling domain.

A

True!

43
Q

What are the 5 receptor families for cytokines and chemokines?

A
  1. Type I cytokine receptor
  2. Type II cytokine receptor
  3. TNF receptor family
  4. IL-1 receptor family
  5. 7 transmembrane G-protein coupled receptors
44
Q

What does the Type 1 Cytokine receptor accept?

A

IL-2, 4, 5, 6 12 & 13 are in this family.

*Signal via Jak-STAT cascades

45
Q

What does the Type II cytokine receptor accept?

A

IFN-gamma & IL-10

  • Signal via Jak-STAT
  • Similar to Type I except cytokine binding domain differs
46
Q

Tell me about the TNF Receptor Superfamily….

A

TNF-alpha belongs here

* Multiple signaling cascades can be induced, can lead to transcription factor expression OR apoptosis

47
Q

Tell me about the IL-1 Receptor family…

A

Receptor for IL-1 belongs here.
Signaling has many similarities to the Toll-like receptors
*Conserved Cytosolic sequence called the Toll-like/IL-1 receptor domain activates IRAK! IRAK initiates the signaling cascade.

48
Q

Tell me about the 7 Transmembrane G-Protein coupled receptors….

A

Receptor for all the Chemokines!
- 7 transmembrane receptors
Signaling via G-Proteins
Rapid and transient signaling cascade.