Chapter 16,Innate Immunity：Nonspecific Defenses of the Host,2007/05/28,2,Q&A,During one year, nosocomial infections occurred in 74 patients in one hospital. All 74 patients were incubated and mechanically ventilated. The infections were caused by Burkholderia cepacia transmitted in nonsterile mouthwash.,Why did these patients develop infections while others who used the mouthwash were not infected?,2007/05/28,3,Host Defenses (宿主的防禦),An Overview of the Bodys Defenses,ANIMATION Host Defenses: The Big Picture,Figure 16.1,2007/05/28,4,Nonspecific Defenses of the Host 宿主的非專一性防禦,16-1 Differentiate innate and adaptive immunity. 16-2 Define Toll-like receptors. The Concept of Immunity Susceptibility Lack of resistance to a disease. Immunity Ability to ward off disease.(Resistance) Innate immunity Defenses against any(Nonspecific resistance) pathogen. Adaptive immunity Immunity, resistance to a(Specific resistance) specific pathogen.,2007/05/28,5,Nonspecific Defenses of the Host,Pathogen-associated molecular patterns (PAMPs) ：Host Toll-like receptors (TLRs) attach to various components commonly found on pathogens. TLRs induce the defensive cell to release chemicals called cytokines. TLRs induce cytokines that regulate the intensity and duration of immune responses.,The Concept of Immunity,2007/05/28,6,Microbial antagonism/competitive exclusion： Normal microbiota compete with pathogens or alter the environment. Commensal microbiota： One organism (microbe) benefits and the other (host) is unharmed. May be opportunistic pathogens,Normal Microbiota and Innate Immunity (Nonspecific resistance) 正常菌叢與非專一性抗性,2007/05/28,7,Skin： Epidermis：consists of tightly packed cells with Epithelial cells： Consists of with tightly packed cells. Langerhans cells： Participate in immunity by assisting helper T (TH) cells. Keratin： A protective protein. Dermis： Connective tissue.,First Line of Defense Skin and Mucous Membranes Physical (Mechanical) Factors,2007/05/28,8,Keratin Epidermis Dermis,2007/05/28,9,Physical (Mechanical) Factors,Mucous membranes： Mucus: Traps microbes Ciliary escalator： Microbes trapped inmucus are transportedaway from the lungs.,Fig.16.4 The Ciliary escalator,2007/05/28,10,Physical Factors,Lacrimal apparatus： Washes eye Saliva： Washesmicrobes off Urine： Flows out Vaginal secretions： Flow out,Fig. 16.3 The lacrimal apparatus,2007/05/28,11,Q & A,During one year, nosocomial infections occurred in 74 patients in one hospital. All 74 patients were intubated and mechanically ventilated. The infections were caused by Burkholderia cepacia transmitted in nonsterile mouthwash.,Why did these patients develop infections while others who used the mouthwash were not infected?,2007/05/28,12,Fungistatic unsaturated fatty acid in Sebum. Low pH (3-5) of the skin： Secretion of fatty acid and lactic acid. Low pH (1.2-3.0) of gastric juice. Low pH (3-5) vaginal secretions. Lysozyme： Breaking down cell wall of bacteria. Is found in perspiration, tears, saliva, tissue fluids, and urine. Antimicrobial chemicals： Transferrins in blood find iron. NO inhibits ATP production.,Chemical Factors (化學因子),2007/05/28,13,Phagocytes,Phago = eat + Cyte = cell Phagocyte Ingestion of a microorganism or any particulate matter by a cell. Phagocytosis. Second line ofdefense. All of which aretypes of whiteblood cells orderivatives ofwhite blood cells.,2007/05/28,14,Table 16.1,Formed Elements In Blood,4000-10000/ml,Red Blood Cells,White Blood Cells:,Transport O2 and CO2,Phagocytosis,Histamine,Kill parasites,Neutrophils,Basophiles,Eosinophils,Monocytes,Phagocytosis,T cells & B cell,Platelets,Blood clotting,B cell : Produce antibodies,T cell : Cell-mediated immunity,2007/05/28,15,Percentage of each type of white cell in a sample of 100 white blood cells,Differential White Blood Cell Count 鑑別白血球總數,Leukocytosis (白血球增多症)： Leukopenia (白血球減少症)：,2007/05/28,16,Granulocytes： Neutrophils：Phagocytic Polymorphonuclear leukocytes (PMNs) Basophils： Produce histamine Eosinophils： Toxic to parasites, some phagocytosis Monocytes： Phagocytic as mature macrophages Fixed macrophages in lungs, liver, bronchi Wandering macrophages roam tissues Lymphocytes: Involved in specific immunity,White Blood Cells,2007/05/28,17,Components of Lymphatic System,Tonsil (扁桃腺),Lymphatic vessel (淋巴管),Thymus gland (胸腺),Large intestine (大腸),Bone marrow (骨髓),Heart (心臟),Thoracic duct (胸管),Lymph node (淋巴結),Spleen (脾臟),Small intestine (小腸),Peyers patch (白氏淋巴集結),Lymph node (淋巴結),Left subclavian vein (左鎖骨下靜脈),Left subclavian vein (左鎖骨下靜脈),Thoracic duct (胸管) (left lymphatic duct 左淋巴管),Right lymphatic duct (右淋巴管),2007/05/28,18,ANIMATION Host Defenses：Overview,Components of the Lymphatic System,(小靜脈),(小動脈;微動脈),(血液),(靜脈),(血液),(細胞間液),(淋巴液),(淋巴微管),(細胞間液),(淋巴微管),(淋巴液),(組織細胞),(微血管),2007/05/28,19,Principal kinds of leukocytes,單核球,Dendrites cells,Phagocytosis,Natural killer cells,Destroy target cells,2007/05/28,