Chemokines and Cytokines of Innate Immunity Flashcards
what cytokines do type I cytokine receptors receive?
most ILs, GM-CSF, G-CSF, M-CSF
what cytokines do type II cytokine receptors receive?
all IFNs, IL-10, IL-20, IL-24, IL-26
tumor necrosis factor (TNF) is produced by _____ in response to _____
activated macrophages, T cells, NK cells and mast cells bacterial lipopolysaccharide (LPS) binding to TLR and IFN-gamma from T cells and NK cells
TNF - functions
acute inflammatory response to gram-negative bacteria
stimulates recruitment of neutrophils and monocytes
induces vascular endothelium to express selectin and chemokines for chemotaxis
stimulates monocytes to produce IL-1
activates apoptotic pathway
hypothalamus: endogenous pyrogen -> cytokine stimulated secretion of prostaglandins
hepatocytes: induces acute-phase response -> formation of CRP
septic shock - effects
TNF inhibits myocardial contractility and vascular smooth muscle tone -> tachycardia, hypotension
thrombosis: inhibits thrombomodulin, stimulates tissue factor
low blood glucose: overuse by muscles, underproduction by liver
interleukin-1 (IL-1) is produced by _____ in response to _____
activated macrophages, neutrophils, epithelial/endothelial cells
TLR activation by LPS or pattern recognition
IL-1 - functions
induces fever induces acute-phase proteins induces neutrophil and platelet production DOES NOT INDUCE APOPTOSIS DOES NOT (by itself) CAUSE SEPTIC SHOCK
interleukin-12 (IL-12) is produced by _____ in response to _____
activated APCs (dendritic cells, macrophages) TLR activation by LPS, intracellular bacteria/viruses, and APCs stimulating T cells
IL-12 - functions
stimulates IFN-gamma production from NK and T cells
gram-negative sepsis: increased IL-12 induces increased IFN-gamma which, along w/ LPS, induces large amounts of TNF -> septic shock
functions in T helper differentiation
type I interferons (IFNs) are produced by _____ in response to _____
dendritic cells/macrophages (IFN-alpha) and fibroblasts (IFN-beta)
viral nucleic acids and macrophages
IFNs - fxns
induce proteins that inhibit viral replication machinery increase MHC class I expression (of viral proteins)
interleukin-10 (IL-10) is produced by _____ in response to _____
activated macrophages, Tregs and non-lymphoid cells
NF-kappaB release
IL-10 - fxns
inhibits innate immune response
limits production of IL-12 -> IFN-gamma
inhibits MHC class II expression
negative feedback
summarize the innate immune response to extracellular bacteria
TNF, IL-1 and chemokine release
promotion of extravasation
main responder: neutrophils
summarize the innate immune response to intracellular bacteria
IL-12 and IFN-gamma release
promotions of phagocytosis
stimulation of adaptive immune response
main responder: macrophages
