Cytokines (midterm) Flashcards
What are the type I interferons?
- IFN-α
- IFN-β
What are the type II interferons?
- IFN-γ
What cells secrete type I interferons?
- Plasmacytoid dendritic cells in response to viruses
- Conventional dendritic cells, macrophages, B cells, endothelial cells as a consequence of TLR3/TLR4 activation
What is the function of type I interferons?
- Sequestration of lymphocytes in secondary lymphoid organs
The antiviral state: - Increased cytotoxicity of CD8+ T cells/NK cells
- Upregulation of MHC-I proteins
- Decreased RNA translation
- Increased activity of RNAases
- Increased activity of GTPases
Which cytokines are responsible for the antiviral state?
Type I interferons (IFN-α, IFN-β)
What cells secrete type II interferons?
- NK cells
- CD4+ TH1 cells
What is the function of type II interferons?
- Classical (M1) activation of macrophages to kill intracellular pathogens
- Class-switching of B cells to IgG
Which cytokines are responsible for classical (M1) activation of intracellular pathogens?
Type II interferons (IFN-γ)
Which cytokines are responsible for class-switching to IgG?
Type II interferons (IFN-γ)
Which cells secrete tumor necrosis factor (TNF)?
- NK cells
- Macrophages
- Dendritic cells
-
Not epithelia or neutrophils
(All via the action of TLRs, NLRs, or RLRs)
The fact that TNF is not produced by epithelia or neutrophils is the main difference between TNF and IL-1
What are the functions of TNF?
- Increasing NK cell cytotoxicity
Local inflammatory effects: - Increasing expression of adhesion molecules on endothelial cells
- Stimulation phagocytes to release cytokines and chemokines for inflammation and leukocyte chemotaxis
Systemic protective effects: - Fever
- Stimulating leukocyte production in the bone marrow
Systemic pathologic effects: - Decreased cardiac output
- Formation of thrombi in blood vessels
- Insulin resistance in skeletal muscle
Which cytokines are responsible for induction of fever?
- TNF
- IL-1
- IL-6
Which cytokine increases the cytotoxicity of NK cells?
TNF
Which cytokines are responsible for increased production of acute phase proteins?
- IL-1
- IL-6
Which cytokines increase expression of adhesion molecules on endothelial cells?
- TNF
- IL-1
To which family of cytokines does BAFF (BLyS) belong?
Tumor necrosis factors
(Not sure if this is required)
What is the function of BAFF (BLyS)?
Preventing activated B cell death
What is the function of Bcl-2?
(Not a cytokine)
An anti-apoptotic protein in B cells
Damage to the BCL2 gene is implicated in chronic B lymphocytic leukemia
Which cells secrete IL-17?
CD4+ TH17 cells
What is the function of IL-17?
Leads to recruitment of macrophages and neutrophils (via release of other cytokines)
What cells secrete IL-12?
- Macrophages
- Dendritic cells
What is the function of IL-12?
Activation of NK cells
What is the receptor through which NK cells are activated?
FcγRIIIA
What is the receptor through which basophils, eosinophils, and mast cells are activated?
FcεRI
What cells secrete IL-15?
- Macrophages
- Dendritic cells
What is the function of IL-15?
Activation of NK cells
What cells secrete IL-4?
CD4+ TH2 cells
What is the function of IL-4?
- M2 activation of macrophages
- Class-switching to IgE
What cells secrete IL-13?
CD4+ TH2 cells
What is the function of IL-13?
M2 activation of macrophages
What cells secrete IL-13?
CD4+ TH2 cells
What is the function of IL-13?
M2 activation of macrophages
What cells secrete IL-18?
- Macrophages
- Dendritic cells
- Neutrophils
- Some epithelial cells
(Via action of the NLRP class of NLRs)
What is the function of IL-18?
Pro-inflammatory mediator
What cells secrete IL-1?
- Macrophages
- Dendritic cells
- Neutrophils
-
Epithelial cells
(Via the combined action of NLRs and TLRs)
What are the functions of IL-1?
Local inflammatory effects:
* Increasing expression of adhesion molecules on endothelial cells
* Stimulation phagocytes to release cytokines and chemokines for inflammation and leukocyte chemotaxis
Systemic protective effects:
* Fever
* Production of acute phase proteins
* Stimulating leukocyte production in the bone marrow
Systemic pathologic effects:
* Insulin resistance in skeletal muscle
What cells produce IL-6?
- Macrophages
- Dendritic cells
- Neutrophils
- Epithelial cells
What is the function of IL-6?
- Promotes formation of TH17 cells
Systemic protective effects: - Fever
- Production of acute phase proteins
- Stimulating leukocyte production in the bone marrow
What is the function of IL-8?
CXCL8—promotes chemotaxis and phagocytosis
What cells secrete IL-8?
- Macrophages
- Epithelial cells
- Endothelial cells
- Airway smooth muscle cells
What is the ligand of CXCR5?
CXCL13
What cells secrete CXCL13?
Follicular dendritic cells
What is the receptor for CXCL13?
CXCR5
What is the ligand for CCR19/CCR21?
CCL7
What is the receptor for CCL7?
CCR19/CCR21
Where does the gradient of CXCL13 lead?
Secondary follicles (B cell zones)
Where does the gradient of CCL7 lead?
Marginal zone of T cell zone
What is the function of transforming growth factor beta (TGF-β)
Class-switching to IgA