医学免疫学课件：调节性T细胞在1型糖尿病治疗中的应用

1、调节性T细胞在1型糖尿病治疗中的应用Application of Regulatory T cells in Treatment of Type 1 Diabetes MellitusPart 1:Regulatory T cells1-1Introduction 调节性T细胞(regulatory T cell, Treg)，指能抑制其他免疫细胞活化、增殖的一种T细胞亚群，在维持自身稳定、防止自身免疫性疾病、抑制排异反应的发生中发挥重要作用，并参与肿瘤的免疫逃逸。https:/1-2Classification按来源不同：胸腺 - 自然发生调节性T细胞 (naturally occurrin

2、g Treg, nTreg)外周 - 诱导性调节性T细胞 (induced regulatory T cells, iTreg)按细胞表面标志：CD4调节性T细胞 CD4+CD25+Foxp3+ 510% of CD4+ T cellsCD8调节性T细胞双阴性T细胞1-3Molecular characterizationCD25：Sakaguchi等首次提出将CD25分子可作为Treg细胞的表面标志（1995年）Foxp3：转录因子forkhead box P3(Foxp3)可作为Treg细胞的细胞内标志（2003年）DNA methylation analysis：foxp3基因上特定结构

3、域发生DNA低甲基化（2013年）Ohkura N, Kitagawa Y, Sakaguchi S. Development and maintenance of regulatory T cellsJ. Immunity, 2013, 38(3): 414-423.T Cell Subpopulations Delineated by CD25, Foxp3, and the Treg-Cell-Type EpigenomeOhkura N, Kitagawa Y, Sakaguchi S. Development and maintenance of regulatory T cells

4、J. Immunity, 2013, 38(3): 414-423.A Model for Treg Cell Development in the ThymusGoldilocksOhkura N, Kitagawa Y, Sakaguchi S. Development and maintenance of regulatory T cellsJ. Immunity, 2013, 38(3): 414-423.Figure 1. Functional Significance of Treg-Cell-Type Epigenetic ChangesHOPE A S F O F. Foxp3

5、: Important regulatory gene for the development of regulatory T-cellsJOther Treg markers：CD3, neuropilin-1, CD103, GPR83, GITR, CTLA4.Sakaguchi S, Yamaguchi T, Nomura T, et al. Regulatory T cells and immune toleranceJ. Cell, 2008, 133(5): 775-787.Differentiation of Naive CD4+ T Cells into Tregs or E

6、ffector T Cells1-4DevelopmentSakaguchi S, Yamaguchi T, Nomura T, et al. Regulatory T cells and immune toleranceJ. Cell, 2008, 133(5): 775-787./2007/02/yxmyx/kc/kcnr/Word/yxmyx/images/image075.jpgCampbell D J, Koch M A. Phenotypical and functional specialization of FOXP3+ regulatory T cellsJ. Nature

7、Reviews Immunology, 2011, 11(2): 119-130.Figure 1. Functional differentiation of TReg cells and TH cells.1-5FunctionTreg细胞功能特征免疫无能性：对IL-2、APC、抗原的刺激呈低反应状态免疫抑制性：高浓度IL-2存在下，通过TCR刺激，可活化增殖，抑制CD4+和CD8+细胞的活化增殖Sakaguchi S, Yamaguchi T, Nomura T, et al. Regulatory T cells and immune toleranceJ. Cell, 2008, 1

8、33(5): 775-787.Key Roles of IL-2 in Immune HomeostasisMarekTrzonkowska N, Myliwec M, Siebert J, et al. Clinical application of regulatory T cells in type 1 diabetesJ. Pediatric diabetes, 2013, 14(5): 322-332.Treg细胞作用方式通过分泌抑制性细胞因子发挥免疫调节作用通过细胞间直接接触发挥作用1-6Tregs and diseases自身免疫性疾病 Tregs发挥免疫抑制作用，维持机体自身免

9、疫耐受，防止自身免疫病的发生。慢性感染性疾病 病毒持续低水平感染时，Tregs调控病原体诱导的有效T细胞应答与导致严重炎症及组织破坏的过度T细胞反应之间的平衡，即“抗感染免疫与免疫病理损伤的平衡”。炎症性肠病 Tregs能够维持肠道免疫稳态，功能紊乱时可能导致肠道黏膜免疫系统对肠道非致病抗原的异常反应发生炎症。肿瘤 Tregs在肿瘤的免疫逃逸中发挥重要，抑制抗肿瘤T细胞的免疫应答。Sakaguchi S, Yamaguchi T, Nomura T, et al. Regulatory T cells and immune toleranceJ. Cell, 2008, 133(5): 775

10、-787.器官移植免疫耐受IPEX Syndrome (Immunodysregulation Polyendocrinopathy Enteropathy X-linked syndrome) (Foxp3 mutation)：发生在小于六个月男婴身上，出现脱落性皮炎，严重性水泻和1型糖尿病等临床症状 Ethan Shevach and Todd Davidson. January 2010 Vol 10 No 1. Produced with support from STEMCELL TechnologiesRegulatory T cellsPart 2:Diabetes mellit

11、us type 12-1Introduction Diabetes mellitus type 1 (DM1), is a form of diabetes mellitus that results from the autoimmune destruction of the insulin-producing beta cells in the pancreassubsequent lack of insulin increased blood and urine glucoseclassical symptoms including polyuria (frequent urinatio

12、n), polydipsia (increased thirst), polyphagia (increased hunger), weight loss/wiki/File:Main_symptoms_of_diabetes.pngFigure 1. Main Symptoms of Diabetes2-2PathophysiologyAn autoimmune response towards beta cells:an expansion of autoreactive CD4+ T helper cells and CD8+ T cellsautoantibody-producing

13、B cellsactivation of the innate immune systemdecrease of Treg ?2-3Prevention & ManagementImmunosuppressive drugsInsulin therapyPancreas transplantationIslet cell transplantationInduce Tregs in DM1 patients ?Part 3:Tregs in Treatment of DM13-1Views on Tregs in DM1(1) number and function of Tregs decr

14、eased in DM1 patients(2) extensively activated autoreactive T cells resistant to physiologically acting TregsFigure 1. In T1D subjects, Tregs isolated from CD4+ T cells have reduced function and increased apoptosis.Jailwala P, Waukau J, Glisic S, et al. Apoptosis of CD4+ CD25 high T cells in type 1

15、diabetes may be partially mediated by IL-2 deprivationJ. 2009.Figure 2. Model of tuned suppression: an immune response primes the regulation required for its safe resolutionWalker L S K. Regulatory T cells overturned: the effectors fight backJ. Immunology, 2009, 126(4): 466-474.tuned suppression3-2D

16、ifficultiesSafety(1) DM1 is not associated with imminent death(2) affects mainly the most vulnearby patients - childrenDifficulties of Treg cell treatment(1) complex phenotype of Treg cells(2) low percentage of Tregs in the periphery(3) loss of activity during ex vivo expansion3-3Animal ExperimentsT

17、regs can prevent destruction of pancreatic islets and fully protect from the development of autoimmune diabetesShortagesrelative doses of Tregs are higherfellow up only few weeksthe time of administration after Treg isolation is shorter3-4Approaches to induce Tregs in DM1 patientsOral insulin admini

18、strationanti-CD3 antibody treatmentPhase I - antibody binds to CD3 and induces apoptosis of activated T cellsPhase II - increase iTregs and iTregs produce IL-10 and TGF-autoantigen-based vaccine treatmentGAD-alumDiaPep277Vitamin D3 treatmentIsolation and ex vivo expansion of nTregs for clinical admi

19、nistrationFigure 1. Therapy with natural regulatory T cells(nTregs): outline of the procedureMarekTrzonkowska N, Myliwec M, Siebert J, et al. Clinical application of regulatory T cells in type 1 diabetesJ. Pediatric diabetes, 2013, 14(5): 322-332.3-5Clinical ImmunologyThe release criteria for the fi

20、nal Tregs product1) FoxP3 expression above 90% 2) passed IFN suppression assay3) negative microbiological testsmeasuring items:(1) metabolic responses: fasting C-peptide, glucagon, fasting glucose, HbA1c(2) immune responses: immunization response to hepatitis B, rubella viruses(3) FoxP3+CD4+CD3+ Tre

21、gs Figure 1. C-peptide, daily doses of insulin, HbA1C and fasting glucose in studied groupsFigure 1. Correlation between % of Tregs and serum C-peptide levelMarek-Trzonkowska N, Myliwiec M, Dobyszuk A, et al. Therapy of type 1 diabetes with CD4+ CD25 high CD127-regulatory T cells prolongs survival o

22、f pancreatic isletsResults of one year follow-upJ. Clinical Immunology, 2014, 153(1): 23-30.Figure 1. Correlatiion between % of Tregs and daily insulin dose (DID).Marek-Trzonkowska N, Myliwiec M, Dobyszuk A, et al. Therapy of type 1 diabetes with CD4+ CD25 high CD127-regulatory T cells prolongs surv

23、ival of pancreatic isletsResults of one year follow-upJ. Clinical Immunology, 2014, 153(1): 23-30.3-6Perspectives Success of Treg cells in treatment of Type 1 Diabetes MellitusFurther improvementtherapeutic effect of Tregs wanes with timeconfirm safety and efficacyReferencesSakaguchi, S., et al. (20

24、08). Regulatory T cells and immune tolerance. Cell 133(5): 775-787.Ohkura, N., et al. (2013). Development and maintenance of regulatory T cells. Immunity 38(3): 414-423.Brode, S., et al. (2006). Cyclophosphamide-Induced Type-1 Diabetes in the NOD Mouse Is Associated with a Reduction of CD4+CD25+Foxp3+ Regulatory T Ce