Cytokines in health and disease Flashcards Preview

Immunology & Inflammation > Cytokines in health and disease > Flashcards

Flashcards in Cytokines in health and disease Deck (16)
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1
Q

What are the 5 different roles of cytokines?

A
  1. cell growth
  2. cell differentiation
  3. healing
  4. tissue remodeling
  5. REGULATE IMMUNE RESPONSES
2
Q

What are the 5 general features of cytokines?

A
  • Pleiotrophic: each cytokine has several different functions
  • Redundancy: an animal without IL‐6 can perform all functions ascribed to IL‐6
  • Production: inducible, short half life
  • Synergy: acts together for enhanced effect
  • Antagonism: counteract each other
3
Q

What are the 4 modes of action of cytokines?

A
  1. Endocrine: targets peripheral cells (IL-6, IL-1, TNF,…)
  2. Paracrine: immediate proximity (IL-1, TNF,…)
  3. Autocrine: acts on producer cell (IL-2,…)
  4. Gradient-dependent: in tissue (IL-8)
4
Q

What are the 5 factors that regulates the effect of a cytokine?

A
  1. extracellular abundance
  2. receptor concentration
  3. signalling cascade activation
  4. cell type (response can vary depending on the cell type)
  5. decoy receptor (receptor having no effect on the cell => a way to regulate reaction)
5
Q

At first infection, what cytokine is secreted and what other cytokines does it induce?

A

TNF is first secreted, then IL-1ß and IL-6

6
Q

What is TNF, what does it do, where is it found and which cells produce them?

A
  1. TNF = Tumour necrosis factor
  2. Regulation of proliferation & apoptosis + pro-inflammatory (pleiotropic)
  3. Membrane‐bound form and soluble form => both active
  4. Produced mainly by: mononuclear phagocytes, activated T‐cells, mast cells & NK‐cells
    => TNF is vital for host defense against intracellular bacteria and parasites
7
Q

What are the cell-bound TNF receptors and where can they be found?

A
  1. p55: present on all cell types apart from erythrocytes, constitutive expression
  2. p75: more abundant on immune cells, inducible expression
    => both can be shed during inflammation and lead to activation of pro-inflammatory signals
8
Q

What can down-regulate the production of TNF?

A

TNF production down-regulated by prostaglandins, IL‐ 6, IL‐10 and corticosteroids

9
Q

What cells produce IL-1a & IL-1ß and what induces their production?

A

IL‐1a & IL‐1ß produced by: mononuclear phagocytes, B‐cells, NK‐cells, neutrophils, keratinocytes, epithelial cells and endothelial cells
Production induced by: DAMPs, PAMPs, TNF and IL‐1 (induced by itself)

10
Q

What are the effects of IL-1?

A

Local: activates vascular endothelium (adhesion molecules), activates lymphocytes (co-activator), local tissue destruction and macrophage activation
Systemic: fever, corticosteroid production, production of IL‐6 & almost all other cytokines, bone marrow stimulant (for neutrophils) and
does not kill cells! (contrary to TNF)

11
Q

What is proIL-1ß?

A

It is the inactive form of IL-1ß, needs to be cleaved by ICE to mature into IL-1ß

12
Q

Where and how is IL-6 produced/induced?

A

Produced by a wide variety of cells
Induced by microbes, TNF and IL‐1
Endocrine function
Pleiotropic

13
Q

How does iL-6 resolve innate immunity and induce adaptive immunity?

A

Resolving innate immunity: block TNF & IL-1, induce TNF & IL-1 antagonists, promote neutrophil apoptosis, etc.
Inducing adaptive immunity: block T-cell apoptosis, chemokine receptor expression on T-cells, proliferation of T-cells, Ig-production, etc.

14
Q

What up-regulates and down-regulates IL-6?

A

Up-regulation: TNF, IL‐1 and IFN‐b

Down-regulation: IL‐4, IL‐13 and glucocorticoids

15
Q

What are JAK and STAT?

A

They are signaling pathways for cytokines

16
Q

What are immune checkpoint inhibitors?

A
  • Suppression of T‐cell activation by PD‐1 and CTLA‐4 is considered one of the major escape mechanisms of cancer cells
  • Inhibition of these molecules by immune checkpoint inhibitors can successfully activate the immune system to fight cancer