微生物學-16-宿主的非專一性防禦.ppt

2007/05/28 * Fever are also systemic, or overall, responses; an abnormally high body temperature. Hypothalamus is sometimes called the body’s thermostat, and it is normally set at 37°C. G(－) endotoxin cause phagocytes to release interleukin 1 (IL-1). Hypothalamus releases prostaglandins that reset the hypothalamus to a high temperature, thereby, causing fever. Body increases rate of metabolism and shivering (chill) to raise temperature When IL-1 is eliminated, body temperature falls. (This phase of the fever, called the crisis) Fever：Abnormally High Body Temperature 2007/05/28 * Fever Advantages Increases transferrins Increases IL–1 activity Produces Interferon Disadvantages Tachycardia Acidosis Dehydration 44–46°C fatal 2007/05/28 * Antimicrobial substances The Complement System Complement system destroy microbes by 1.Cytolysis 2.Inflammation 3.Phagocytosis Components： Over 30 proteins produced by the liver and found circulating in blood serum, and activated in a cascade. 2007/05/28 * Antimicrobial SubstancesThe Complement System Serum proteins activated in a cascade activated by Antigen-antibody reaction Proteins C3, B, D, P and a pathogen C3b causes opsonization C3a + C5a cause inflammation C5b + C6 + C7 + C8 + C9 cause cell lysis ANIMATION Complement System: Activation ANIMATION Complement System: Overview ANIMATION Complement System: Results 2007/05/28 * Pathways of activation Classical Pathway： cytolysis Antigen-Antibody Complex + C1 C2 C2a + C2b C3a (MACs) C9 + C4 C4a + C4b C3b C5 C5b,C6,C7,C8 Alternative pathway： Cell wall polysacchrides + factor B, D, P. + C3 C3a + C3b cytolysis inflammation Opsonization Lectin (Mannose-binding protein) pathway： Lectin bbindin to mannose on the microbes surface C2 C2a + C2b C3a inflammation C4 C4a + C4b C3b opsonization, cytolysis C3 C3 The Complement S