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ID:56961111
大小:2.04 MB
页数:66页
时间:2020-07-22
《肿瘤免疫生化医学医药课件.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、TumorImmunobiochemistry1.ThesurveillianceSystemandcancer2.Naturalkiller(NK)cell3.Antibody4.MHCproteinsFordecades,theimmunesurveillancesystemhasbeencreditedwithprotectingthebodyagainstcancer.Presumably,cancerdevelopsoccasionallyduringalifetimeandthesurveillancesystemisabletoeradicateitfromth
2、ebody.1.ThesurveillanceSystemandcancerItisonlywhenacancerescapesthissystemorthesystembecomesweakenedthatcancercanbecomeestablished.Insomecases,thecancercellsareable,biochemically,toescapetheimmunesurveillancesystem.机体的抗肿瘤免疫效应机制包括细胞免疫和体液免疫细胞免疫的效应细胞包括T细胞,NK细胞,巨噬细胞,目前认为中性粒细胞、嗜酸性粒细胞也参与抗肿瘤作用。激活补
3、体系统溶解肿瘤细胞,抗体依赖的细胞介导的细胞毒作用,抗体的调理作用,抗体封闭肿瘤细胞上的某些受体,抗体使肿瘤细胞的粘附特性改变或丧失ThesurveillianceSystem2.Naturalkiller(NK)cellNKcellsaresubsetofTcellsthatcankilltumorcells(orvirus-infectedcells)butdonotharmnormalcellsNKcellsalsoareheterogeneous;theycontainsubsetsofcells,atleastoneofwhich(A-NKcells)iscapa
4、bleofkillingtumorcellsandcellsinfectedwithvirusesTheA-NKcellhasavarietyofreceptorsonitscellularsurfaceTu15-12Tu15-12Tu15-12图15-1OneormoreofreceptorswillrecognizeanantigenonthesurfaceofthetumorcellThisantigen,notexpressedonmostnormalcells,isanMHCclassIchain-relatedantigen,theantigenbindsto
5、NKG2D,ac-lectin-likereceptoronthesurfaceofhumanNKcellsThecomplexwiththeantigencaninitiatethekillingprogramthroughpI3kNKG2Disnon-covalentlyassociatedtotheDAP10transmembranesignalingadaptor.Killercellshaveatleasttwomechanismstodestroytumorcells*perforin-granzyme-mediatednecrosis*FasL/Faspat
6、hwayinduceapoptosisTu15-12Tu15-3Tu15-3Tu15-3Tu15-3Tu15-4WhycanNKcellkilltumorcellsbutdonotharmnormalcellsTwoofreceptorsonthesurfaceoftheNKcellarekillercellinhibitoryreceptorKIR,(KIR2DL2),anexampleofanimmunoglobulin-likereceptor,andLy-49A,normalcellsexpressanMHCclassIchain-relatedantigeneith
7、eratverylowlevelsornotatall,andA-NKcellsthataresurveyingthemicroenvironmentdonotattackthemontheotherhand,NKcellshavereceptorsthatrecognizenormalantigensonnormalcells;thiscomplexinhibitsthekillingprogramTu15-9Tu15-103.AntibodyAntibodies(Abs)arespecificmol
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