Cvtokines Lu Qing, PhD, MD Department of Immunology School of Medicin, Fudan University Tel:5423-7093 E-mail:fuqing@fudan.edu.cn
Cytokines Lu Qing, PhD，MD Department of Immunology School of Medicin, Fudan University Tel：5423-7093 E-mail: fluqing@fudan.edu.cn
What are cytokines? Cytokines are soluble protein secreted by the cells of innate and adaptive immunity and therefore mediate many of the functions of these cells Based on their cellular sources monokines(mononuclear phagocyte lymphokines(ymphocytes interlukin (leukocytes(IL-1,IL-2, etc.) O A subfamily of cytokines primarily functions in directing migration of cells, these are called chemotactic cytokines"or chemokines
What are cytokines? ⚫ “Cytokines” are soluble protein secreted by the cells of innate and adaptive immunity and therefore mediate many of the functions of these cells ⚫ Based on their cellular sources monokines (mononuclear phagocyte) lymphokines (lymphocytes) interlukins (leukocytes) (IL-1, IL-2, etc.) ⚫ A subfamily of cytokines primarily functions in directing migration of cells, these are called “chemotactic cytokines” or “chemokines
Cytokines ● General Properties o Functional Categories of Cytokines ● Cytokine Receptors ● Biologic Actions
Cytokines ⚫ General Properties ⚫ Functional Categories of Cytokines ⚫ Cytokine Receptors ⚫ Biologic Actions
Cytokines ● General Properties o Functional Categories of Cytokines ● Cytokine Receptors ● Biologic Actions
Cytokines ⚫ General Properties ⚫ Functional Categories of Cytokines ⚫ Cytokine Receptors ⚫ Biologic Actions
Innate and adaptive Immunity Microbe Innate immunity Adaptive immunity B lymphocytes Epithelial Antibodies barriers T lymphocytes Phagocytes Effector T cells Complement NK cells Hours Days 6 Time after infection Figure 1-1 Innate and adaptive immunity. The mechanisms of innate immunity provide the initial defense against infections. Adaptive immune responses develop later and consist of activation of lymphocytes. The kinetics of the innate and adaptive immune responses are approximations and may vary in different infections
Innate and adaptive Immunity
Phagocytes-identify, ingest, and destroy microbes O Mononuclear phagocytes O Neutrophils(polymorphonuclear leukocytes) Short-lived(6h); the most abundant population of circulating WBCs mediate the earliest phase of inflammatory response
Phagocytes-identify, ingest, and destroy microbes ⚫Mononuclear phagocytes ⚫Neutrophils (polymorphonuclear leukocytes) Short-lived (6h); the most abundant population of circulating WBCs; mediate the earliest phase of inflammatory response
(b) Bacterium becomes attached to membrane evaginations called pseudopodia Bacterium is ingested, forming phagosome Phagosome fuses with lysosome 00( Lysosomal enzymes digest captured material a Digestion products are released from cell
Bacterium becomes attached to membrane evaginations called pseudopodia Bacterium is ingested, forming phagosome Phagosome fuses with lysosome Lysosomal enzymes digest captured material Digestion products are released from cell (a) (b)
NK cells-kill infected cells and tumor cells o perforin/granzyme(cytolysis) ●Fas/FasL Cell apoptosis ●TNF/ TNFR-I Release of granules at site of cell contact c Figure 8-29 part 3 of 3 Immunobiology, 6/e (0 Garland Science 2005)
NK cells-kill infected cells and tumor cells ⚫ perforin/granzyme (cytolysis) ⚫ Fas/FasL ⚫ TNF-/TNFR-I Cell apoptosis
As a result of cellular activation Mononuclear phagocytes are the principal source of cytokines of innate immunity e Tumor necrosis factor (tNF ●lL-1 lL-12 ● Type I IFNs ●lL-15 ●lL-18 NK cells secret cytokine, mainly IFN-y--to activate macrophage to destroy phagocytosed microbes
NK cells secret cytokine, mainly IFN-g—to activate macrophage to destroy phagocytosed microbes. ⚫ Tumor necrosis factor (TNF) ⚫ IL-1 ⚫ IL-12 ⚫ Type I IFNs ⚫ IL-15 ⚫ IL-18 Mononuclear phagocytes are the principal source of cytokines of innate immunity As a result of cellular activation:
Innate and adaptive Immunity Microbe Innate immunity Adaptive immunity B lymphocytes Epithelial Antibodies barriers T lymphocytes Phagocytes Effector T cells Complement NK cells Hours Days 6 Time after infection Figure 1-1 Innate and adaptive immunity. The mechanisms of innate immunity provide the initial defense against infections. Adaptive immune responses develop later and consist of activation of lymphocytes. The kinetics of the innate and adaptive immune responses are approximations and may vary in different infections
Innate and adaptive Immunity