联合应用共刺激通路阻断剂诱导小鼠记忆性心脏移植耐受的研究  

Combined costimulation blockade inhibits accelerated rejection mediated by alloantigen-primed memory T cells in mice

作　　者：解百宜[1] 陈继冰[2] 夏俊杰[1] 王永志[1] 梁华[3] 齐忠权[1] 

机构地区：[1]厦门大学器官移植研究所,厦门361005 [2]厦门大学医学院基础医学部 [3]厦门大学附属中山医院心脏外科

出　　处：《中华细胞与干细胞杂志（电子版）》2012年第1期17-22,共6页Chinese Journal of Cell and Stem Cell（Electronic Edition）

摘　　要：目的 探索联合应用共刺激通路阻断剂诱导记忆性心脏移植耐受的方法。方法 皮肤预致敏小鼠,过继转移同种反应性记忆性T细胞(Tm),构建小鼠同种异体心脏移植模型后再联合阻断效应及Tm激活途径,通过观察各组移植物平均存活时间、移植物排斥程度,检测脾脏中CD44高表达细胞数、脾细胞增殖情况和移植物中相关基因相对表达量等指标探讨其可能的作用机制。结果 (1)未处理小鼠脾脏中Tm占6.52﹪,而预致敏小鼠脾脏中Tm占26.5﹪;(2)平均存活时间为对照组5.17d,联合应用CTLA4Ig和anti-CD40L(二联用药)组10.33d,再联合应用anti-LFA-1和anti-OX40L(四联用药)组均>100d;(3)移植物排斥对照组均为4级,二联用药组?3B级,四联用药组为0级;(4)只有对照组脾脏物中CD44高表达;(5)对照组与二联用药组脾细胞增殖程度(t=2.91,P=0.027)明显高于四联用药组;(6)治疗组的移植物中IL-2、IFN-γ和Foxp3基因的表达量明显低于对照组(t=6.51,t=9.94,t=6.15,P=0.00,P=0.00,P=0.00),并且四联用药组IL-10基因表达量明显升高(t=4.71,P=0.003)。结论 对于记忆性心脏移植模型,只有联合阻断效应和Tm才可获得移植物长期耐受,其机制可能是明显降低移植物和移植受者细胞免疫应答水平的同时,诱导移植物中表达大量IL-10分泌性Tr1细胞。Objective The present study was undertaken to induce the tolerance of cardiac allografts in mice by combined costimulatory blockade. Methods Before the surgery, alloreactive memory T cells （Tm） from alloantigen-primed mice were adoptively transferred to the mice recipients of heterotopic cardiac transplant. After the transplant, we treated the mice with combined costimulatory blockade to inhibit the activation of both effector T ceils and Tm. HE staining was used to evaluate rejection. Mean survival time （MST） of the cardiac grafts was compared among the groups. CD44 cells number in the spleen, proliferation of spleen cells and expression of immune-related genes and the possible mechanisms were evaluated. GraphPad Prism~ was used for statistic analysis. Results （1）The percentage of Tm was 6.52 % in naive mice vs 26.5 % in alloantigen-primed mice; （2） The MST was 5.17 days in the untreated group （Group A）, and 10.33 days in the group receiving CTLA4Ig and anti-CD40L treatment （Group B）. For mice in Group C given CTLA4Ig, anti-CD40L, anti-LFA-1 and anti-OX40L, MST was over 100 days; （3） In the histological evaluation, the mean scales were 4, 3B and 0 for the above 3 groups respectively; （4） CD44high T cells were observed in the untreated group only. （5）The OD values of mixed lymphocyte reaction（MLR） were over 0.6 for both Groups A and B, and less than 0.4 for Group C （t = 2.91, P = 0.027）; （6）The gene expression levels of IL-2, IFN-7 and Foxp3 were lowest in Group C, followed by Group B and Group A（t = 6.51, t = 9.94, t = 6.15, P = 0.00, P = 0.00, P = 0.00）. In contrast, the expression levels of IL-10 were highest in Group C（t = 4.71, P = 0.003）. Conclusions Inhibiting both effect T cells and Tm could induce the tolerance of cardiac grafts and prevent the allografts from T cell infiltration. The mechanisms might be that the treatment promotes the functions of IL-10 producing CD4＋ type 1 regulatory T （Trl） cells, while suppresses the cellular immunity of

关 键 词：共刺激通路阻断 加速性排斥 记忆性T细胞 心脏移植 免疫耐受 

分 类 号：R654.2[医药卫生—外科学]