3 Cytokines Flashcards
Proteins secreted by cells that mediate the functions of the immune system. Soluble proteins/glycoproteins. Regulate the intensity and duration of the immune response. Necessary for leukocyte activation.
Cytokine
Cellular sources of cytokines
- Lymphocytes
- Monocytes/Macrophages
- Innate and adaptive immune cells
- Endothelial/epithelial cells
The term _____ refers to the fact that many proteins are produced by one immune cell to act on neighboring cells.
Interleukin
Cytokine secretion is ____ and self-limited
Brief
Cytokine action is pleitropic and _____
Redundant
T/F Cytokines influence each other
True
Cytokine receptor ligation leads to _____ which alters cellular function
Gene expression
The principal mediator of the acute inflammatory response to Gram-negative bacteria, endotoxic shock, and chronic inflammatory conditions. Made mainly by monocytes, macrophages, NK cells, DC cells, and T cells. Stimulates recruitment of neutrophils, monocytes, activated T cells.
TNF-alpha
Low concentrations of TNF-alpha in blood plasma can be ____. How?
Moderate concentrations can be ____. How?
High concentrations can be ____. How?
Beneficial. Cellular recruitment and activations of macrophages and T cells
Beneficial. Fever, migration of cells out of bone marrow, more acute phase proteins
BAD. Less muscle contractions (hypotension), blood clots (sticky immune cells), depleted glucose from liver
Primarily produced by mononuclear phagocytes and neutrophils. Shares many same effects of TNF-alpha.
IL-1
Primarily produced by macrophages and T cells. Involved with induction of inflammatory response, but primarily induction of acute phase response.
IL-6
Primary mediator of innate immune response to intracellular pathogens. Important for generation of adaptive immune response that would be appropriate for intracellular pathogens.
IL-12
IL-12 importance for innate immunity is in activation of ____. But IL-12 does NOT _____ _____. Instead it stimulates ____ secretion from leukocytes which does the actual activation.
Macrophages
Activate macrophages
IFN-gamma
Macrophages that phagocytose a pathogen can kill the pathogen when they are exposed to _____
IFN-gamma
Needed for growth, survival, and differentiation of T cells. Clonal expansion is dependent on this. Produced by T helper cells
IL-2
Adaptive immunity most effective against intracellular pathogens is _____ cytokines.
Adaptive immunity most effective against extracellular pathogens is ____ cytokines
Th1 (T helper type 1)
TH2
A key Th2 cytokine. Can induce naive Th cells to differentiate into Th2 cells. Primary stimulus for Ig class switching to IgE
IL-4
Very similar to IL-4. Primary job is to help induce Ig isotype switching to IgE. Also stimulates mucous production in gut and lung. Can facilitate inflammation by increasing adhesion molecule and chemokine expression.
IL-13
Primary job is in eosinophil differentiation, proliferation, and activation. Eosinophils are necessary for protection against parasites.
IL-5
An inhibitory cytokine produced by macrophages, dendritic cells, and T helper cells. Primary function is to inhibit IL-12 production by activated macrophages.
IL-10
Chemotactic cytokines. Regulate migration of cells to peripheral tissues or lymph nodes
Chemokines
Receptors for IL-2, 4, 5, 6, 12, 13 are in this family. Signal via Jak-STAT cascades.
Type 1 Cytokine Receptor
Receptors for IFN-gamma and IL-10. Signals via Jak-STAT. Similar to Type I except the extracellular cytokine binding domain differ.
Type II Cytokine Receptors
Receptor for TNF-alpha belongs to this family. Multiple signaling cascades can be induced, can lead to transcription factor expression OR apoptosis.
TNF Receptor Superfamily
Receptor for IL-1 belongs to this family. Similar to Toll-like receptors. Conserved cytosolic sequence (Tir) domain that activates IRAK to signal cascade.
IL-1 Receptor Family
Chemokine receptors that signal via G-proteins. Rapid and transient signaling cascade.
7 Transmembrane G-protein-coupled receptors.
