Principles of Immunology Cytokines 2/2/06 “Live simply so others can simply live.” Anonymous.
-
date post
21-Dec-2015 -
Category
Documents
-
view
222 -
download
0
Transcript of Principles of Immunology Cytokines 2/2/06 “Live simply so others can simply live.” Anonymous.
Word List
Autocrine Endocrine Immunoglobulin superfamily Interleukin Paracrine Pleiotropy Stem cell factor
Chemical Structure
Low molecular weight proteins, <30kD
High affinity for receptors Active in picomole amounts
Chain of Cytokine Action
Stimulus>Cytokine-producing cell>
Cytokine>Target cell>Receptor>
Biological effect(s)
Names of Cytokines
Source e.g.,Lymphokines
Function e.g.,Chemokines
Intercellular action e.g., Interleukins
Action of Cytokines Autocrine
Affects the generating cell (self)
Paracrine Affects cells in the immediate vicinity
Endocrine Affects cells remote from the secreting
cell
Action of Cytokines Pleiotropy
Affects multiple cell types Redundancy
Multiple cytokines affects cells of the same type Synergy
Cytokines acting in concert on the same cell Antagonism
Competing actions Cascading
Cytokines acting sequentially
Cytokine-generating Cells Innate immunity
Macrophages Endothelial cells Fibroblasts
Adaptive immunity T lymphocytes Macrophages NK cells
Cytokine Receptors
Multimeric receptors Common signal-transducing subunits Unique high affinity subunits High affinity subunits associated with
activation of target cell
Signal Transduction
Initiated by cytokine binding Activates JAK (Janus kinase) Phosphorylation of tyrosine Binding of STAT(Signal transducers
and activators of transcription) Translocation of STAT to cell’s DNA Transcription of specific target genes
Role of Cytokines in Hematopoiesis
SCF (Stem cell factor) GM-CSF (Granulocyte-macrophage
colony-stimulating factor) IL-3 (Interleukin 3) IL-5 (Interleukin 5) IL-7 (Interleukin 7) IL-11(Interleukin 11)
Cytokines in the Immune Response
Innate immune response IL 1-(Macrophage)-fever, capillary effects IL 6-(Macrophage)-adaptive immunity via B cells IL 12(Macrophage)-adaptive immunity via T
helper cells TNF (Macrophage)-capillary effects, activates
neutrophils IFN alpha (Macrophage)-multiple effects IFN beta (Fibroblasts)-multiple effects
Cytokines in the Immune Response
Adaptive immune response IL 2-(T cells)-multiple effects) IL 4-(T cells & mast cells)-T cell
differentiation, IgE production TGF beta –(T cells, macrophages)-inhibits
adaptive immune response IFN gamma-(T cells, NK cells)-
Macrophage activation
Subsets of T helper Cells T helper 1
IgG production/Complement fixation Macrophage activation DTH CTL production
T helper 2 IgE production Eosinophils