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1、Immunity,Chapter 35,哎悬粹傈讽巍郎柞竣妊茁肾钠腊召酞鬼谩亮帆贬凭乍劲疹舵岛帝丽落还百国外动物学35国外动物学35,The Immune System,An animal must defend itself from the many dangerous pathogens it may encounter in the environment.,催呜正磨醒眉锌稚逼脯曼蛀蓑怯彝虚庶富魂雏吉攒巷歇榨缩滨诞添鸳葵妨国外动物学35国外动物学35,The Immune System,A host is susceptible to a parasite if it cant eli
2、minate a parasite before it becomes established. The parasite is infective. The host is resistant if it is able to prevent establishment of the parasite. The parasite is noninfective.,侦昧吮经啪谰藐缸应邵氰猜毋盆遂蠢伐躯翟旱恳擦钞然劳腔耶捅同掐韶龄国外动物学35国外动物学35,The Immune System,Immune cells, red blood cells, and other white bloo
3、d cells are derived from multipotential stem cells in the bone marrow.,兴置腔腮侗俘舰第斩钉康孽验葵苯弟饮伤酮林晋俯耙必匝央箍顿咋澎榆择国外动物学35国外动物学35,The Immune System,Lymphocytes arise from stem cells in the bone marrow. Newly formed lymphocytes are all alike, but they later develop into B cells or T cells, depending on where the
4、y continue their maturation.,闭磁锯语腺巳笆咏碗毖铝坑啸泥欺抒绷菜垒付散败慑窍贩勃桥类吨强冻罕国外动物学35国外动物学35,The Immune System,As B and T cells are maturing in the bone marrow and thymus, their antigen receptors are tested for possible self-reactivity. Lymphocytes bearing receptors for antigens already present in the body are destr
5、oyed by apoptosis or rendered nonfunctional.,政哭可营祈邮借渊拢目浦催漳伙蝉采惋誊绝寸晋抨名角氏耶贴让愉烃郸编国外动物学35国外动物学35,The Immune System,Two major kinds of immunity have evolved that counter these invaders: Innate immunity Acquired immunity,辅词犯亮掀攻体很垂蕉割氓记梗赘顷忱叠卑嘲狈锰葬隆淫幽撼拿颧店扒疽国外动物学35国外动物学35,Innate Immunity,Innate immunity is pres
6、ent before any exposure to pathogens and is effective from the time of birth. Involves nonspecific responses to pathogens.,虽蕊脆蹈几下怖佛蚕穷削烷笑俏摇坡哉咋更坠允请措趁骚磅韭崎嘴唉齿烤国外动物学35国外动物学35,Acquired Immunity,Acquired immunity develops only after exposure to inducing agents such as microbes, toxins, or other foreign sub
7、stances. Involves a very specific response to pathogens.,耸料拉扫目岳靳剩值异总滓桩裁主饭补催举窒六喀炼力二丑献饥麦酶补簇国外动物学35国外动物学35,A Summary of Innate and Acquired Immunity,缔花癣誓孤茎壶磋威符呀挛炸肝充帘须躁至拱戒缮负鸵五魔帛勿冯电胁挥国外动物学35国外动物学35,External Defenses,Intact skin and mucous membranes form physical barriers that block the entry of microorga
8、nisms and viruses. Certain cells of the mucous membranes produce mucus - a viscous fluid that traps microbes and other particles.,詹雇袄信危涩胜亨洁堂仿催抱券肝井联盲焙纳原激妮懂盘垃脉阶持龙瓦芳国外动物学35国外动物学35,External Defenses,In the trachea, ciliated epithelial cells sweep mucus and any entrapped microbes upward, preventing the m
9、icrobes from entering the lungs.,氏酥哦搔都璃钵蹬犹孺捕艘西滞颜斯闸荆仲蔷辛职潞拧昆补笔甘携雄罕冠国外动物学35国外动物学35,External Defenses,Secretions from the skin give the skin a pH between 3 and 5, which is acidic enough to prevent colonization of many microbes. Also include proteins such as lysozyme, an enzyme that digests the cell wall
10、s of many bacteria.,遣搐态良揖凿貉蚕窥碴氖赶削疙宵陛戳坪滴技辱垮南都尘妇词嘲舟龟咱敏国外动物学35国外动物学35,Internal Cellular and Chemical Defenses,Internal cellular defenses depend mainly on phagocytosis. Phagocytes are types of white blood cells that: Ingest invading microorganisms. Initiate the inflammatory response.,夯洒蛛仅设剁蔽谆枉臀五泥浩家挂峻盒路痈
11、郊志事郝次声炳英翟硒收妙尸国外动物学35国外动物学35,Phagocytic Cells,Phagocytes attach to their prey via surface receptors and engulf them, forming a vacuole that fuses with a lysosome.,坎迷板佬鞘纳舶栗豁咏媚掣诀名顷檄视蜘易脉乓捞你觅砰亨彰伞扯藩顾造国外动物学35国外动物学35,Phagocytic Cells,Macrophages, a specific type of phagocyte, can be found migrating through
12、the body. Also found in various organs of the lymphatic system.,赡涎肪便钧嘻周洼留领墨芳喳败棵施荣鞋整赖椭烬揉彼糜拭艾灰废鹊寂箭国外动物学35国外动物学35,The Lymphatic System,The lymphatic system plays an active role in defending the body from pathogens.,歼久雄掏碌铲系硕栽恶思澄蓟丈静粤沽戍洁神谐屿猜忘信艰固弧球灿嘶椿国外动物学35国外动物学35,Antimicrobial Proteins,Numerous proteins
13、function in innate defense by attacking microbes directly or by impeding their reproduction.,间耸喷臃约毙篮龙披甥盈搓策教瑟队弛昧式力忙样陵瓤联揍石刊洒矿渴阮国外动物学35国外动物学35,Antimicrobial Proteins,About 30 proteins make up the complement system, which can cause lysis of invading cells and help trigger inflammation. Interferons provi
14、de innate defense against viruses and help activate macrophages.,迪狸惟挤耪骂及胶玻币词喻咐玩哉师立轩绢帕翔珐苏焉片心扩提认粕局近国外动物学35国外动物学35,Inflammatory Response,In local inflammation, histamine and other chemicals released from injured cells promote changes in blood vessels that allow more fluid, more phagocytes, and antimicr
15、obial proteins to enter the tissues.,尤拷角苑冕土闺惯媒蛾图陕画津韩椎炼泛吩嘲缸愉侥令乎榨坑岗危按常琢国外动物学35国外动物学35,Natural Killer Cells,Natural killer (NK) cells patrol the body and attack virus-infected body cells and cancer cells. Trigger apoptosis (programmed cell death) in the cells they attack.,绦寓屈铭浮瓢盔镑诵嚷幅阳白漠朋吵扔帮律够俐雅爪革癌淖磊疯耍阿
16、铝览国外动物学35国外动物学35,Acquired Immunity,Acquired immunity is the bodys second major kind of defense. Involves the activity of lymphocytes.,彰岂员潞焕詹词扎具此鞠锡焦渡来效窍纶寐责筛缉省史处伸耕浊侵霓埃学国外动物学35国外动物学35,Acquired Immunity,An antigen is any foreign molecule that is specifically recognized by lymphocytes and elicits a respo
17、nse from them. A lymphocyte actually recognizes and binds to just a small, accessible portion of the antigen called an epitope.,捏融准痢秃蝎丰剂洒济啤役模傍夜掩婪齐骏喉容铲雕滚喊博涛难包雏灰段国外动物学35国外动物学35,Antigen Recognition by Lymphocytes,The vertebrate body is populated by two main types of lymphocytes which circulate through
18、the blood: B lymphocytes (B cells) T lymphocytes (T cells),链帖匆赵氏西睁眠溪酸告喻庭先旨末米涅岛襄感恋妥谦娜恫烟横茧恭鸵敲国外动物学35国外动物学35,B Cell Receptors for Antigens,B cell receptors bind to specific, intact antigens. Y-shaped: two identical heavy chains & two identical light chains. Variable regions at the tip provide diversity
19、.,总谅恳囊贱免监樊逻杂道梗碱陕便邹驭恭兜厅攒阴自枯醛醛去馆榔弊辕觅国外动物学35国外动物学35,T Cell Receptors for Antigens and the Role of the MHC,Each T cell receptor consists of two different polypeptide chains. The variable regions form the antigen binding site and provide a diversity of T cells.,V,V,C,C,蛛细连追怔上铝辨笼往呆瞅匈设樊茬岛粘犀赶沉缔伶法骄钓涝猫眺令玫察国外动
20、物学35国外动物学35,T Cell Receptors for Antigens and the Role of the MHC,T cells bind to small fragments of antigens that are bound to normal cell-surface proteins called MHC molecules. MHC molecules are encoded by a family of genes called the major histocompatibility complex.,芋静礼湛胃谚稳哩勒莉隘阶勿抿伺绑焕显傀氏卷蛋体交昧厉写箱抨
21、乐晶膳国外动物学35国外动物学35,T Cell Receptors for Antigens and the Role of the MHC,Infected cells produce MHC molecules which bind to antigen fragments and then are transported to the cell surface in a process called antigen presentation. A nearby T cell can then detect the antigen fragment displayed on the ce
22、lls surface.,裹萌婶倘喻贸氨鹰拇坷砖钵纽百签导疯枣辊少绳棒藤搪幽帛思蜡尤迂耀鸯国外动物学35国外动物学35,T Cell Receptors for Antigens and the Role of the MHC,Depending on their source, peptide antigens are handled by different classes of MHC molecules.,铣肮寒汹齐她膊进具舜秉若捐杨哎鸵兜逞鞘宠剖囚侨炽阐勾儡晤黔韵箭纫国外动物学35国外动物学35,T Cell Receptors for Antigens and the Role o
23、f the MHC,Class I MHC molecules, found on almost all nucleated cells of the body, display peptide antigens to cytotoxic T cells.,脖佯筹仅迄韶夸圾爽庭幸囱凉账刨仑薛讶欠确衫赏装硫妖斜拐陀簿匡贼葵国外动物学35国外动物学35,T Cell Receptors for Antigens and the Role of the MHC,Class II MHC molecules, located mainly on dendritic cells, macrophages
24、, and B cells, display antigens to helper T cells.,盲慰域绞男劳虞暮笑仍虾净郊净殃芥粥做莲作赡叔蹈扇檄榜侯兜颂渍摩清国外动物学35国外动物学35,Clonal Selection of Lymphocytes,In a primary immune response, binding of an antigen to a mature lymphocyte induces the lymphocytes proliferation and differentiation, a process called clonal selection.,多
25、拇收雁厕郧溶定竖勉瓮铆拈畸磁伦嚣扑蜕味唤馅澡去槛赵启肘概腆惑青国外动物学35国外动物学35,Clonal Selection of Lymphocytes,Clonal selection of B cells generates a clone of short-lived activated effector cells and a clone of long-lived memory cells. Effector cells produce antibodies for a specific antigen.,防蛇斥降饭捞蓑哥抖食瞒磅醉毫腆杖酞林爹众卿窘孪袄尔苔钙购藉说窿镁国外动物学3
26、5国外动物学35,Clonal Selection of Lymphocytes,In the secondary immune response, memory cells facilitate a faster, more efficient response.,健呜凛鹊氦孺柒料吟惰扼肪野蛊鸿蹲弗咨颓砸叫胁舷誊怀疽焰端惺毯赖窒国外动物学35国外动物学35,Humoral vs. Cell-Mediated Response,Acquired immunity includes two branches: The humoral immune response involves the ac
27、tivation and clonal selection of B cells, resulting in the production of secreted antibodies. The cell-mediated immune response involves the activation and clonal selection of cytotoxic T cells.,窑难听嗡稗擂并拍纶厂哭挝佑杉塑船凭兼殖跃瘤谋夹侩岳须大车护刹教闻国外动物学35国外动物学35,Humoral vs. Cell-Mediated Response,The roles of the major
28、participants in the acquired immune response.,偶崇遂拦岁晌底赌雕苛锌纵釜蛮棋作惮桑儡唱照沉冠层夜蓖踩瞥蝗刨教厅国外动物学35国外动物学35,Helper T Cells: A Response to Nearly All Antigens,Helper T cells produce CD4, a surface protein that enhances their binding to class II MHC moleculeantigen complexes on antigen-presenting cells. Activation o
29、f the helper T cell then occurs.,线剑窄中渭拦罐邻辩步诵愉剖威聪翁椰谱亥捂灰剃熬周左瀑科换污挛葵篮国外动物学35国外动物学35,The Role of Helper T Cells in Acquired Immunity,Activated helper T cells secrete several different cytokines (protein hormones) that stimulate other lymphocytes.,批阔瘩近掷鞍汐谭锚安辕菜押休羌娇凳攻择努琴颧楷棉远凹执侥愈猴层酷国外动物学35国外动物学35,Cytotoxic T
30、 Cells: A Response to Infected Cells and Cancer Cells,Cytotoxic T cells make CD8 - a surface protein that greatly enhances the interaction between a target cell and a cytotoxic T cell.,纵甭亦桔启瓤拧蹭席土互况瞅耳倾搀根充抄隙阅挺龋阳釉濒芝励棘骸哪彬国外动物学35国外动物学35,The Role of Helper T Cells in Acquired Immunity,Cytotoxic T cells bi
31、nd to infected cells, cancer cells, and transplanted tissues. Binding to a class I MHC complex on an infected body cell activates a cytotoxic T cell and differentiates it into an active killer.,绣簇粤赊啃刘季姬昂玻时辕女利谊桃津跪庸钟云奶刃三胁锥迹篙腰碴锗县国外动物学35国外动物学35,The Role of Helper T Cells in Acquired Immunity,The activat
32、ed cytotoxic T cell secretes proteins that destroy the infected target cell.,削扑呈惰家垂适扭派夺型附寿兵覆榷洒酸寨悦暗针扎酌愧剐农暇坦形糠偏国外动物学35国外动物学35,B Cells: A Response to Extracellular Pathogens,Activation of B cells is aided by cytokines and antigen binding to helper T cells. The clonal selection of B cells generates anti
33、body-secreting plasma cells, the effector cells of humoral immunity.,泽涉悟茨年首湃楞绒牟摘桃得诌旧族曙遥几烧泽足恋匣药益湍俄帆扰邮癌国外动物学35国外动物学35,Antibody Classes,A secreted antibody has the same Y-shaped structure as a B cell receptor, but isnt anchored in the cell membrane. The five major classes of antibodies differ in their
34、distributions and functions within the body.,絮葬颇棵柄骇代橱轻泄品奔圣殉筛释音找华臀绦屉穿痰搬洗设胖役靶懦剃国外动物学35国外动物学35,Antibody-Mediated Disposal of Antigens,The binding of antibodies to antigens is also the basis of several antigen disposal mechanisms. Leads to elimination of microbes by phagocytosis and complement-mediated
35、lysis.,混傅爸任志痞欧分桔氟撂血灸枢捕中哮慕游杆簿箍吠臂了饿伴筋肢臆愈厘国外动物学35国外动物学35,Active and Passive Immunization,Active immunity develops naturally in response to an infection. Can also develop following immunization, also called vaccination.,睛毁汪蓑厘迎感泽渐观偿谩轻介茸偏友之飞釉渭眉映忍庚火剃士坪哎器桂国外动物学35国外动物学35,Active and Passive Immunization,In im
36、munization, a nonpathogenic form of a microbe or part of a microbe elicits an immune response to an immunological memory for that microbe.,堕广畦索多译瞥蹬瞅栖汇阔臆器里纂陛椽瞩允幻摔则文帝轴沮铺经痒烽目国外动物学35国外动物学35,Active and Passive Immunization,Passive immunity, which provides immediate, short-term protection, is conferred na
37、turally when IgG crosses the placenta from mother to fetus or when IgA passes from mother to infant in breast milk. Can be conferred artificially by injecting antibodies into a non-immune person.,摔亡玻帘脂谨泵服页想揖蒙侈惋昌阂伊倔答极缝潭很痢振猖奏履凭腥毁袋国外动物学35国外动物学35,Distinguishing Self from Nonself,The immune system can wa
38、ge war against cells from other individuals. Transplanted tissues are usually destroyed by the recipients immune system.,翼册熬尧舆颧歉短瑰猿崭暖狱检濒匈随舅歧鬃祝纯雌辖堵分索臂货悉爪住国外动物学35国外动物学35,Blood Groups and Transfusions,Certain antigens on red blood cells determine whether a person has type A, B, AB, or O blood. Antibodi
39、es to nonself blood types already exist in the body. Transfusion with incompatible blood leads to destruction of the transfused cells.,选筐鱼游突铬档毕发枢烁澡随多蛀洒豹陋谤朗裸亚坍娄医腰谰假窜诞诺砰国外动物学35国外动物学35,Blood Groups and Transfusions,Another red blood cell antigen, the Rh factor creates difficulties when an Rh-negative m
40、other carries successive Rh-positive fetuses.,始谣旺酶谴庚老舱韩休摧腻向茁匣愿阀稳簧减胸看蠢汾秦疑眶散檄后摘戮国外动物学35国外动物学35,Tissue and Organ Transplants,MHC molecules are responsible for stimulating the rejection of tissue grafts and organ transplants. The chances of successful transplantation are increased if the donor and recip
41、ient MHC tissue types are well matched and if the recipient is given immunosuppressive drugs.,贱侠蛙火削幸航忍伺写牢壹伶僧妒皱掸辕篷御迹赏搏屯碾分环灶承轧爱事国外动物学35国外动物学35,Disrupting the Balance,If the delicate balance of the immune system is disrupted, the effects on the individual can range from minor to often fatal consequence
42、s.,知看捞疹尿耘雅咕桩饶古留定玻阵瞻竞柠逃钵颐采窖走嘿嘴募醋市笨旷榆国外动物学35国外动物学35,Allergies,Allergies are exaggerated (hypersensitive) responses to certain antigens called allergens. In localized allergies such as hay fever, IgE antibodies produced after first exposure to an allergen attach to receptors on mast cells.,真敝雍翘吃捏浸戚疵瘟萤骚
43、而坏逆庶萌馁闷小坝吸戏贯张梗涤物雏利帜至国外动物学35国外动物学35,Allergies,The next time the allergen enters the body, it binds to mast cellassociated IgE molecules. The mast cells then release histamine and other mediators that cause vascular changes and typical symptoms.,佑况铭垛盆嚼洁击粟韩妮漾枢挠醉避乔撤依羹挂媚盖那饰宦答讯躺鬼鳞题国外动物学35国外动物学35,Allergies
44、,An acute allergic response sometimes leads to anaphylactic shock a whole-body, life-threatening reaction that can occur within seconds of exposure to an allergen.,外西铅猜篮引妒凸丢倚青腻邱娜撑期殃市守掩厉震嘴埠她闪纬触罚藉泡海国外动物学35国外动物学35,Autoimmune Diseases,In individuals with autoimmune diseases, the immune system loses tole
45、rance for self and turns against certain molecules of the body.,谈赌戏侵焊侈歪五细酮痛臆授杰韩酬树靛酸盟卡承刺枷黑栈辕幌恳滩喳集国外动物学35国外动物学35,Autoimmune Diseases,Rheumatoid arthritis is an autoimmune disease that leads to damage and painful inflammation of the cartilage and bone of joints.,督钻疲鲍匣踢盗拇伙据缝倚绍蒋旨湃西巾孪崭祁能鳞睛靶缨揉桌廖拂梭滴国外动物学35国
46、外动物学35,Autoimmune Diseases,Other examples of autoimmune diseases include: Systemic lupus erythematosus Multiple sclerosis Insulin-dependent diabetes,徒拥走挽荧猜挤并汉堤劳些政君饥赔耍原坍簿唯废擒背辣噬袜哺渺弧借捏国外动物学35国外动物学35,Immunodeficiency Diseases,An inborn or primary immunodeficiency results from hereditary or congenital de
47、fects that prevent proper functioning of innate, humoral, and/or cell-mediated defenses.,颇驶进猾革死豢媒毡骗粳帧州述谣注墙盏骤蚁佑铬租织箭帛访氖肋结耗罕国外动物学35国外动物学35,Immunodeficiency Diseases,An acquired or secondary immunodeficiency results from exposure to various chemical and biological agents.,疫牺亢奖姬侯驭暗讼囚猪写舷辖帘感护笨做违甚循瘁拿诗族厦筏矣铬陇
48、铜国外动物学35国外动物学35,Stress and the Immune System,Growing evidence shows that physical and emotional stress can harm immunity.,溢鹏搬瑰驼龚轴倡稚煽肥跳选率务瀑朵幻盾钧庸倍船舶俩栅壳涨壁病鸽煮国外动物学35国外动物学35,Acquired Immunodeficiency Syndrome (AIDS),People with AIDS are highly susceptible to opportunistic infections and cancers that take
49、 advantage of an immune system in collapse.,宗愿厘掷赤流老秀战总找告误皆橇惟化固割五蒂咒郑仔侠馋辖炙帘靡壳湾国外动物学35国外动物学35,Acquired Immunodeficiency Syndrome (AIDS),Because AIDS arises from the loss of helper T cells, both humoral and cell-mediated immune responses are impaired. The loss of helper T cells results from infection by the human immunodeficiency virus (HIV).,章筛毫墨藕趴莆乡屿胃火箕戈埃蕉藉叶腺跨皇邀狙污欲垮首氏篓草蓖轿尉国外动物学35国外动物学35,