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Section 6 cytokines. Chapter 1 introduction. CYTOKINE (CK). Many critical interactions among cells of IS are controlled by soluble mediators (CK) A diverse group of intercellular signaling peptide and glycoproteins with small MW. Several hundred have been identified to date
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Section 6 cytokines
Chapter 1 introduction
CYTOKINE (CK) • Many critical interactions among cells of IS are controlled by soluble mediators (CK) • A diverse group of intercellular signaling peptide and glycoproteins with small MW
Several hundred have been identified to date • The source of CK • Immune cells • Other non-immune cells • some tumor cells
Be secreted by particular cell types in response to a variety of stimuli • Produces characteristic effects on the growth , mobility, differentiation, or function of target cells
Multiple functions • regulate immune and inflammatory responses • healing, hematopoiesis, angiogenesis, et al
Potent compounds with low concentration • By binding to specific surface receptors on target cells • Produced locally by a variety of tissues and cells
Most CK act in paracrine or autocrine manner • Only a few CK act in endocrine manner
Classification • lymphokines: the CK produced by lymphocytes • monokines: the CK produced by monocytes or macrophages
Complexity of effects • may be secreted individually or coordinated response along with other, unrelated cytokines • Overlap extensively • Antagonistic
Chapter 2 classification and biological activities of CK
classification • interleukins • tumor necrosis factor • interferon • hematopoietic colony stimulationg factors • transforming growth factor • chemokines
Interleukins (IL) • Been assigned a number • Mainly produced by leukocyte • Some are produced by other cell populations
IL-2 • An autocrine and paracrine growth factor secreted by activated T cell • has very short half-life in the circulation , mainly autocrine and paracrine
IL-2 • critical for activating all types of acquired immune responses • Be essential for clonal T cell proliferation
IL-2 • apoptosis of T cell after prolonged or repeated activation • Two-edged sword that initiates IR but also limits their intensity and duration
tumor necrosis factor, TNF • TNF-αand TNF-β • Induce hemorrhagic necrosis of certain tumors • Wasting syndrome (cachexia) • Take part in IR
interferon, IFN • IFN-/ (typeⅠ) and IFN- (typeⅡ ) • antivirus anti-tumor immune regulation---- typeⅡ typeⅠ
colony stimulating factor, CSF • support the production of particular mature blood cell types from pluripotent stem cells or committed progenitors in the bone marrow • Granulocyte-CSF, G-CSF monocyte-CSF, m-CSF erythropoietin, EPO
Transforming growth factor, (GF) • As a growth factor for fibroblasts that promoted wound healing • As a negative regulator of immunity and hematopoiesis
chemokines • Chemoattractant activity for monocytes and neutrophiles • Multifunctional • Have little or no effect on cell proliferation