Cytokine Functions Flashcards
IL-1
Fever
Acute Inflammation
Activates endothelium to express adhesion molecules
Induces chemokine secretion for WBCs
IL-6
Fever
Acute phase proteins
TNF -a
Activates endothelium, causing WBC recruitment and increased vascular permeability
IL-8
Major chemotactic factor for Neutrophils
IL-12
Induces differentiation of T cells into Th1 cells
Activates NK cells
IL-2
Stimulates growth of all T cells and NK cells
IL-3
Growth and differentiation of all bone marrow stem cells
Functions like GM-CSF
IFN-y
Secreted by NK cells and Th1 cells
Stimulates macrophages to kill phagocytosed pathogens
Activates NK cells to kill virus-infected cells
Increases MHC expression and antigen presentation
IL-4
Induces differentiation of Th2 cells
Promotes growth of B cells
Enhances class switching to IgE and IgG
IL-5
Promotes growth and differentiation of B cells
Enhances class switching to IgA
Stimulates growth and differentiation of eosinophils
IL-10
Attenuates inflammatory response
Decreases expression of MHC class II and Th1 cytokines
Inhibits activated macrophages and dendritic cells
Secreted by regulatory T cells
What are three general actions of interferons?
Downregulate protein synthesis
Upregulate MHC expression
Activate antitumor immunity
What cytokines are secreted by Th1 cells?
IFN-y
IL-2
What cytokines are secreted by Th2 cells?
IL-4
IL-5
IL-6
IL-10
IL-13
What cytokines are secreted by Th17 cells?
IL-17
IL-21
IL-22
What cytokines are released by macrophages?
IL-1
IL-6
TNF-a
IL-8
IL-12
What are the actions of PGI2, PGD2, and PGE2?
Vasodilation and increased vascular permeability
PGE2 also mediates pain and fever
What is the function of LTB4?
Attracts and activates neutrophils
What is the function of LTC4, LTD4, and LTE4?
Vasoconstriction, bronchospasm, increased vascular permeability
Delayed response (after histamine)
I.e. smooth muscle contraction
What is the function of histamine?
Vasodilation and increased vascular permeability
Immediate response
What is the function of C3a and C5a?
Trigger mast cell degranulation, resulting in histamine-mediated vasodilation and increased vascular permeability
C5a - chemotactic for neutrophils
What is the function of C3b?
Opsonin for phagocytosis
What are the key mediators of redness and warmth associated with inflammation?
Histamine
Prostaglandins
Bradykinin
What are the key mediators of swelling?
Histamine
Tissue damage
What are the mediators of pain?
Bradykinin and PGE2
Sensitize sensory nerve endings
What are the pyrogens?
IL-1 and TNF-a increase COX activity in hypothalamus
PGE2 raises temperature set point
What is the role of TNF and IL-1 in neutrophil arrival?
Upregulate cellular adhesion molecules on the endothelium
What are the four principal attractors of neutrophils?
Bacterial products
IL-8
C5a
LTB4
What cytokines are responsible for attenuating and resolving the immune response?
IL-10
TNF-B
Produced by macrophages
