受体来源未成熟树突状细胞诱导大鼠肝移植免疫低反应性的实验研究

目的 研究不负载供者抗原的受者未成熟树突状细胞(immature dendritic cell,imDC)对大鼠肝移植的保护作用,探讨imDC抑制排斥反应的机理.方法 以SD大鼠作为供体,雄性Wistar大鼠作为受体,随机分为4组,每组10只,建立肝移植急性排斥反应模型,移植前对受体进行不同的处理. 对照组: 受体未接受任何处理; 环孢素A(CsA)组: 术后第2 d开始给予CsA[10 mg/(kg*d)]灌胃; 成熟树突状细胞(mDC)组: 受体术前1 d经阴茎背静脉注射受体来源的mDC 1×106个/只; imDC组: 受体术前1 d经阴茎背静脉注射受体来源的imDC 1×106个/只.模型建立后10 d各组随机处死5只,取移植肝脏组织行HE染色和免疫组化(FasL/Fas)染色,观察肝脏组织形态结构和排斥反应,根据Banff评分系统判断排斥反应程度; Western blot分析检测各组Foxp3编码的Scurfin蛋白的表达.另留5只大鼠观察术后存活时间; 收集血标本,全自动生化分析仪测定ALT、TBIL; 双抗体夹心ELISA法检测血清IL-2、IFN-γ、IL-4和IL-10水平.结果 CsA组和imDC组术后大鼠中位生存时间明显长于对照组和mDC组,差异有统计学意义(P＜0.05).移植术后各组大鼠血清生化检查: 对照组和mDC组ALT及TBIL明显高于CsA组和imDC组(P＜0.05); 且IL-2和IFN-γ也明显高于CsA组和imDC组(P＜0.01),但IL-4和IL-10明显低于CsA组和imDC组(P＜0.01).移植肝脏形态学检测: 对照组和mDC组与CsA组和imDC组比较,排斥反应更严重(P＜0.05).Western blot检测: imDC组Foxp3编码的Scurfin蛋白的表达明显高于其他3组(P＜0.05).结论 imDC通过阻断间接识别能明显延长移植物存活时间.imDC可能通过以下机理诱导免疫低反应: 诱导T细胞凋亡; 选择性激活Th2细胞亚群,诱导Th1/Th2偏移; 诱导调节性T细胞产生.     

采用流式细胞微珠法检测肾移植受者体内供者特异性抗体39例

目的 应用流式细胞微珠法检测肾移植受者供者特异性抗体(DSA),并探讨DSA阳性受者的HLA配型及移植物排斥反应发生情况.方法 检测39例亲属肾移植受者移植前、后的DSA,检测供、受者HLA错配情况,记录受者移植后排斥反应的发生情况.分析DSA阳性及阴性受者的HLA错配及排斥反应的发生情况.结果 39例共检测DSA 313次,其中移植前78次,移植后235次,移植前出现DSA阳性的均暂缓手术.5例HLA无错配的受者移植后DSA均为阴性,34例HLA错配的受者移植后12例出现DSA阳性(35.3％,P＜0.05).12例DSA阳性受者中,5例发生排斥反应(41.7％),其排斥反应发生率显著高于DSA阴性的移植受者(7.4％,P＜0.05).发生排斥反应且DSA阳性受者的单抗原微珠免疫荧光强度均值为5723.9±1030.5,高于未发生排斥反应的DSA阳性者的2355.2±609.7(P＜0.05).DSA阳性的受者治疗后,DSA免疫荧光强度有所下降.结论 采用流式细胞微珠法动态监测DSA效果较好,有利于预测和及时防治肾移植后排斥反应.     

乙型肝炎免疫球蛋白预防肾移植后新发乙型肝炎

目的 探讨肾移植受者应用小剂量乙型肝炎免疫球蛋白(HBIG)预防术后新发乙型肝炎的安全性和有效性.方法 回顾性分析单中心2007年1月至2010年6月间肾移植受者的资料,将术前无乙型肝炎的138例受者作为试验组,术前肌肉注射小剂量HBIG,术后定期监测乙型肝炎表面抗体(HBsAb)滴度,根据其滴度调整术后应用HBIG的剂量,持续应用1年或1年以上.将2004年1月至2006年12月间术前无乙型肝炎的196例肾移植受者作为对照组,不采用乙型肝炎预防措施.观察两组移植后新发乙型肝炎的发病率,并记录急性排斥反应发生情况、受者和移植肾1年存活率.结果 随访12个月,试验组仅1例(0.7％)于术后6个月出现新发乙型肝炎,对照组11例(5.6％)出现新发乙型肝炎,其中2例因爆发性肝功能衰竭而死亡.两组新发乙型肝炎发病率的差异有统计学意义(P＜0.05).术后6个月内,试验组有19例(13.8％)发生急性排斥反应,对照组有34例(17.3％)发生急性排斥反应,两组急性排斥反应发生率的差异无统计学意义(P＞0.05).试验组受者1年存活率为97.8％(135/138),移植肾1年存活率为(96.4％,133/138);对照组受者1年存活率为(91.8％,180/196),移植肾1年存活率为(90.3％,177/196).两组受者和移植肾1年存活率的差异有统计学意义(P＜0.05.P＜0.05).结论 小剂量HBIG用于肾移植后预防新发乙型肝炎是安全、有效的.     

急性体液性排斥反应对移植肾预后的影响

目的 探讨急性体液性排斥反应对移植肾预后的影响.方法 共有1098例接受首次尸体肾移植的受者纳入研究.所有受者术后均采用以他克莫司或环孢素A为基础的三联免疫抑制方案,当发生排斥反应时,采用甲泼尼龙冲击治疗,疗效较差者则联合应用莫罗单抗-CD3或丙种球蛋白或行血浆置换进行治疗.术后1年内经病理检查证实,有53例受者发生急性体液性排斥反应(急性体液性排斥反应组),109例发生急性细胞性排斥反应(急性细胞性排斥反应组),其余936例受者术后1年内肾功能稳定(对照组).分析和比较3组受者性别、年龄、术前淋巴毒、HLA抗原错配数、群体反应性抗体(PRA)水平及供肾冷/热缺血时间等冈素间的差异,比较3组受者术后移植肾功能丧失情况及移植肾存活率,分析完全逆转的急性体液性排斥反应与细胞性排斥反应对移植肾预后的影响.结果 3组受者在性别、年龄、术前淋巴细胞毒性试验、供肾冷缺血时间及术后随访时间等方面比较,差异均无统计学意义(P＜0.05).急性体液性排斥反应组和急性细胞性排斥反应组受者在术前HLA抗原错配数、PRA水平及供肾热缺血时间等方面均明显高于对照组,与对照组比较,差异均有统计学意义(P＜0.05).随访期间,急性体液性排斥反应组受者移植肾功能丧失的发生率为27.4%(14/53),明显高于急性细胞性排斥反应组的7.3%(8/109)和对照组的2.2%(21/936),3组间差异均有统计学意义(P＜0.01).通过kaplan-meier生存分析发现,急性体液性排斥反应组受者的移植肾存活率明显低于急性细胞性排斥反应组和对照组(P＜0.01).剔除发生排斥反应后未逆转者,3组间移植肾存活率的比较,差异均无统计学意义(P＞0.05).结论 急性体液性排斥反应明显影响移植肾存活,但完全逆转的急性体液排斥反应并不影响移植肾的预后.     

免疫球蛋白样转录物3和4在肾移植受者树突状细胞中表达的意义

目的 探讨免疫球蛋白样转录物3和4(ILT3和ILT4)在肾移植受者外周血树突状细胞(DC)中的表达情况,并分析其在移植免疫低反应中的作用.方法 选择肾移植后存活5年以上肾功能稳定和慢性排斥反应的受者各10例,分别作为肾功能稳定组和慢性排斥组;另选择10例健康志愿者作为正常对照组.用粒-巨噬细胞集落刺激因子(GM-CSF)和白细胞介素4(IL-4)刺激各组研究对象的外周血单核细胞,诱导培养获得DC.用流式细胞仪测定DC表面分子ILT3和ILT4的表达,并分析各组DC表达的差异;用酶联免疫吸附试验法测定各组血清中ILT3和ILT4的配体HLA-G5的表达水平.结果 ILT3在肾功能稳定组DC中表达水平上调,与正常对照组和慢性排斥组比较,差异有统计学意义(P＜0.05),而ILT4的表达在各组间比较,差异无统计学意义(P＞0.05);肾功能稳定组血清中HLA-G5的表达水平较正常对照组和慢性排斥组显著升高,差异有统计学意义(P＜0.05).结论 长期存活的肾功能稳定受者外周血中高表达ILT3和其配体HLA-G,说明它们可能在外周免疫耐受的诱导和维持中起非常重要的作用.     

他克莫司与环孢素A在高致敏肾移植受者中的应用比较

目的 观察和比较高致敏肾移植受者应用他克莫司(FK506)与环孢素A(CsA)的有效性和安全性.方法 根据术后免疫抑制方案的不同,将147例高致敏肾移植受者(其中术前群体反应性抗体＞50%的首次肾移植受者59例,2次肾移植受者88例)分为FK506组(53例)和CsA组(94例),两组的免疫抑制方案分别为FK506(或CsA)+霉酚酸酯+泼尼松.观察并分析两组受者术后移植肾存活率、血肌酐水平以及并发症的发生率.结果 FK506组术后1、3和5年的移植肾存活率(86.8%、82.3%和75.3%)略高于CsA组(81.9%、75.4%和66.9%),但差异无统计学意义(P＞0.05);FK506组术后1年时血肌酐水平为(100.72±15.88)μmol/L,CsA组为(117.29±11.77)μmol/L,两组比较,差异有统计学意义(P＜0.01);FK506组与CsA组相比,术后急性排斥反应、慢性排斥反应、肝功能损害、高血压和高血脂的发生率显著降低(P＜0.05),而高血糖的发生率明显升高(P＜0.01),两组移植肾功能延迟恢复和感染的发生率无明显差异(P＞0.05).结论 FK506与CsA相比,能有效降低高致敏受者肾移植术后急、慢性排斥反应的发生率,减少术后并发症的发生,提高移植肾的长期存活率,对高致敏肾移植受者是非常有效和安全的.     

肾移植术后血清抗MICA抗体与慢性排斥反应的相关性

目的 探讨肾移植受者的抗MICA抗体水平与慢性排斥反应的相关性及其对移植肾功能的影响.方法 共有105例受者被作为研究对象纳入分析,其中发生慢性排斥反应者(慢排组)43例,移植肾功能正常者(对照组)62例.记录两组受者术前群体反应性抗体(PRA)、HLA抗原错配数、供肾冷缺血时间、出院时血清肌酐(SCr)水平、术后免疫抑制方案以及入组时间(入组时距肾移植手术时间)等资料,并进行比较.受者分组后,抽取受者外周血,检测SCr及抗MICA抗体水平,抗MICA抗体的检测采用Luminex 100免疫磁珠流式细胞仪技术.观察与比较抗MICA抗体阳性受者和抗MICA抗体阴性受者间术后3个月内发生急性排斥反应(AR)的次数和移植肾功能的差异.移植肾功能的评价采用血清肌酐变化率(△SCr/M),即(入组时SCr值-出院时SCr值)/入组时间.结果 两组受者在性别、年龄、HLA抗原错配数、供肾冷缺血时间、术后免疫抑制方案、出院时SCr水平及入组时间的比较,差异均无统计学意义(P＞0.05).分组后,慢排组受者SCr水平和抗MICA抗体阳性受者比例均明显高于对照组,两组比较,差别均有统计学意义(P＜0.01,表1).抗MICA抗体阳性受者术后3个月内发生的AR次数明显多于抗MICA抗体阴性受者,二者比较,差异有统计学意义(P＜0.05).抗MICA抗体阳性受者的△SCr/M为8.3±3.6,明显高于抗MICA抗体阴性受者的2.4±2.6,二者比较,差异有统计学意义(P＜0.05).结论 抗MICA抗体的表达与慢性排斥反应的发生相关,移植前进行MICA配型可减少术后移植肾慢性排斥反应的发生,有助于延长移植肾的长期存活.     

阿来佐单抗行肾移植免疫诱导治疗的有效性和安全性

目的 评价阿来佐单抗行肾移植免疫诱导治疗的有效性和安全性.方法 将89例肾移植受者随机分为试验组(43例)和对照组(46例).试验组于肾移植术前和术后24 h内分别静脉滴注阿来佐单抗15 mg,对照组不接受免疫诱导治疗.受者术后常规应用环孢素A(或他克莫司)+吗替麦考酚酯+泼尼松预防排斥反应.统计两组术后12月内的移植肾功能、急性排斥反应发生率、感染发生率、移植肾功能延迟恢复发生率、移植肾存活率及淋巴细胞计数,并用ImmuKnowTM免疫细胞功能测定法检测受者CD4+T淋巴细胞的三磷酸腺苷(ATP)值.结果 术后12个月内试验组7.0%(3/43)的受者发生病理证实的急性排斥反应,明显低于对照组的23.9%(11/46,P＜0.05).试验组和对照组总体的感染发生率为别为39.5%(17/43)和30.4%(14/46,P＞0.05),两组机会性感染的发生率分另为23.2%(10/43)和17.4%(8/46,P＞0.05).术后3个月内,试验组淋巴细胞计数低于对照组;术后6个月内,试验组CD4+T淋巴细胞ATP值低于对照组.结论 阿来佐单抗行肾移植免疫诱导治疗可维持受者的免疫抑制状态,未见严重不良反应.     

预存供体特异性抗体阳性肾移植6例报告并文献复习

为探讨术前预存供体特异性抗体(DSA)受者的肾移植临床效果,回顾性分析2017～2019年郑州大学第一附属医院收治的6例术前DSA阳性肾移植受者的临床资料并复习相关文献。6例受者术前群体反应性抗体(PRA)、DSA均阳性,其中3例为亲属来源受者,围手术期通过利妥昔单抗、血浆置换、丙种球蛋白及大剂量兔抗人胸腺细胞免疫球蛋白、甲泼尼龙等联合用药方案降低受者体内预存DSA。术后密切关注受者尿量、血肌酐及DSA动态变化。3例亲属肾移植受者中,1例受者术后13 d出现尿量减少,血肌酐升高,怀疑亚临床排斥反应,给予甲泼尼龙冲击治疗2 d后尿量恢复,血肌酐降至正常水平;其余2例亲属肾移植受者均于术后2周尿量及血肌酐恢复正常水平,DSA降至低危水平。另3例为公民逝世后器官捐献来源肾移植(中国Ⅱ类)受者,术前常规激素+兔抗人胸腺细胞免疫球蛋白诱导治疗后行肾移植术,术后均发生抗体介导排斥反应(AMR)导致移植肾功能延迟恢复(DGF)。通过血浆置换、利妥昔单抗、人免疫球蛋白、激素冲击等联合脱敏治疗后,受者体内DSA降低、排斥反应减轻,分别于术后15 d、35 d、27 d移植肾功能恢复。随访至今,6例DSA阳性受者肾功能均恢复良好,中位血肌酐值104(80～131)μmol/L。我中心认为,预存DSA阳性肾移植受者经过有效的术前预处理及围手术期加强免疫抑制治疗,可以取得良好的移植效果;预存DSA阳性肾移植具有可行性及安全性。     

老年活体供肾移植术后供者安全性及受者移植效果的分析

目的 分析老年活体供肾移植术后供者的安全性及受者的移植效果.方法 回顾性分析251例亲属活体供肾移植的临床资料.根据供者年龄,将251例活体供肾移植分为老年供肾组(≥55岁)和中青年供肾组(<55岁),对手术前后两组供、受者的血清肌酐(Cr)、肾小球滤过率(GFR)、内生肌酐清除率(Ccr)、并发症、平均住院时间以及受者的人/肾存活率、急性排斥反应发生率进行比较和分析.结果 老年供肾组和中青年供肾组供者手术前后血Cr水平的差异无统计学意义(P>0.05),而Ccr的差异有统计学意义(P<0.05).老年供肾组与中青年供肾组供者比较,术前总GFR、留存肾GFR及术后10 d留存肾GFR比较,差异均无统计学意义(P>0.05);老年供肾组供者术后10 d与术前的留存肾GFR比较,差异无统计学意义(P>0.05);中青年供肾组供者术后10 d的留存肾GFR较术前明显上升,差异有统计学意义(P<0.05).老年供肾组与中青年供肾组受者比较,手术前后各相应时间点的血Cr水平差异无统计学意义(P>0.05).老年供肾组和中青年供肾组供者平均住院时间分别为(16.67±7.78)d和(16.11±5.89)d(P>0.05),受者平均住院时间分别为(29.61±24.28)d和(28.76±19.27)d(P>0.05).两组受者6个月内急性排斥反应发生率分别为6.50%和5.75%(P>0.05).老年供肾组受者术后死亡1例,中青年供肾组死亡3例,并有1例因急性排斥反应切除移植肾.结论 老年活体供肾移植术前应对供者进行严格的选择,在进行全面系统评估的前提下,可以保证供者术后的安全以及受者的移植效果.     

Peripheral blood dendritic cells in human end-stage heart failure and the early post-transplant period: evidence for systemic Th1 immune responses.

OBJECTIVES: Dendritic cells (DCs) are antigen presenting cells that play a central role in inflammation, allograft rejection and immune tolerance. Myeloid (mDC) and plasmacytoid (pDC) subsets regulate immune reactions by polarising naive T-helper cells into a Th1 or Th2 response, respectively. In this study we examined total peripheral blood DCs, mDC and pDC subsets in chronic heart failure (CHF) and clinical heart transplantation (HTx). METHODS: We compared 16 heart transplant patients before and after HTx to 14 healthy controls. Whole blood was collected pre-HTx and 1-week post-HTx from patients and at corresponding time-points from controls. All patients received induction and maintenance immunosuppression post-HTx. mDCs and pDCs were measured by flow cytometry and were further characterised for maturation and homing potential to the secondary lymphoid organs with CD83 and CCR7, respectively. Data were expressed as absolute numbers/microl whole blood, percentage (%) mDC or pDC of total blood DCs and % positive DCs for CD83 and CCR7. RESULTS: CHF patients had more peripheral blood DCs compared to controls (P<0.01) while only the mDC fraction was increased compared to controls (P=0.01). Percentage CD83(+) and CCR7(+) mDCs was also higher than control levels (P<0.05). One week post-HTx, total DCs, mDCs and pDCs decreased below controls (P<0.001). At the same time % mDCs in peripheral blood increased markedly compared to CHF and control levels (P<0.001). The %CD83(+) mDC, %CD83(+) pDC and %CCR7(+) mDC also returned to control levels and only %CCR7(+) pDC decreased below control levels (P=0.005). CONCLUSIONS: Total peripheral blood DCs are elevated during CHF due to an increase in the mature fraction of the mDC subset suggesting a possible Th1 response in end-stage heart failure. The decrease in total DCs and mature mDCs and pDCs seen post-HTx, probably reflects immunological quiescence through adequate immunosuppression. Peripheral blood DC monitoring may provide a new insight into mechanisms of heart failure and allograft rejection by safe weaning from immunosuppression after clinical HTx.     

Preferential Depletion of Blood Myeloid Dendritic Cells During Acute Cardiac Allograft Rejection Under Controlled Immunosuppression

Allo-Ag presentation to Ag-specific T-lymphocytes by donor or recipient dendritic cells (DCs) induces acute rejection (AR) after solid organ transplantation. It is postulated that myeloid (mDC) and plasmacytoid (pDC) subsets circulate differentially between bone marrow, heart and lymphoid tissues after cardiac transplantation (HTx). We investigated peripheral blood DC subset distribution, maturation and lymphoid homing properties in relation to endomyocardial biopsy (EMB) rejection grade after clinical HTx. Twenty-one HTx recipients under standard immunosuppression were studied in a 9-month follow-up. mDC and pDC numbers were analyzed by flow cytometry in fresh venous whole blood samples collected during the EMB procedures and before histological diagnosis of AR. Subsets were further characterized for maturation marker CD83 and lymphoid homing chemokine receptor CCR7. Although numbers of both DC subsets remained low for the whole post-HTx period, we observed a negative association of mDCs with rejection grade. Repeated measurements analysis revealed that only mDCs decreased during AR episodes. Rejectors had lower mDC numbers after a 3-month follow-up compared to nonrejectors. Furthermore, patients during AR exhibited low proportions of mDCs positive for CD83 or CCR7. These findings suggest peripheral blood mDC depletion in association with selective lymphoid homing of this subset during AR after clinical HTx.     

The effects of renal transplantation on circulating precursor dendritic cells

BACKGROUND: Dendritic cells (DCs) are potent antigen-presenting cells that induce and regulate immune responses. Recent advances allow accurate quantification of peripheral blood (PB) myeloid and plasmacytoid DC populations (mDC and pDC, respectively), although the response to renal transplantation (RT) remains unknown. METHODS: Using flow cytometry, PBDC levels were quantified in patients with end-stage renal disease (ESRD) undergoing renal transplantation. RESULTS: PBDC levels were significantly reduced in ESRD patients pretransplantation compared to healthy controls, with further reduction noted immediately following a hemodialysis session. RT resulted in a dramatic decrease in both subsets, with a greater reduction of pDC levels. Both subset levels were significantly lower than in control patients undergoing abdominal surgery without RT. Subgroup analysis revealed significantly greater mDC reduction in RT recipients receiving antilymphocyte therapy, with preferential binding of antibody preparation to this subset. Samples from later time points revealed a gradual return of PBDC levels back to pretransplant values concurrent with overall reduction of immunosuppression. Finally, PBDC levels were significantly reduced in patients with BK virus nephropathy compared to recipients with stable graft function, despite lower overall immunosuppression. CONCLUSIONS: Our findings suggest that PBDC levels may reflect the degree of immunosuppression in renal allograft recipients. Furthermore, PBDC monitoring may represent a novel strategy to predict important outcomes such as acute rejection, long-term graft loss, and infectious complications.     

Impaired circulating dendritic cell reconstitution identifies rejecting recipients after clinical heart transplantation independent of rejection therapy.

OBJECTIVE: Dendritic cell (DC) mediated allo-antigen presentation to host antigen specific T-lymphocytes initiates acute allograft rejection. We investigated peripheral blood DC (PBDC) incidence and DC subset reconstitution in relation to histological diagnosis of acute cellular rejection (AR) and administration of rejection therapy after clinical heart transplantation (post-HTx). METHODS: Venous blood from 20 HTx recipients under standard immunosuppression was collected during serial endomyocardial biopsy (EMB) prior to administration of rejection therapy in a 9-month follow-up post-HTx. Echocardiographic assessment of allograft function during EMB was performed to distinguish clinical necessity for rejection therapy within histologically rejecting patients (R). Myeloid (mDC) and plasmacytoid (pDC) subsets identified by flow-cytometry were analysed for different ISHLT rejection grades. Circulating PBDC incidence and mDC/pDC ratio were compared sequentially between non-rejecting (NR) recipients and R patients treated (3A(+)) or not-treated (3A(-)) with rejection therapy during follow-up. RESULTS: Eleven samples from biopsy-proven AR episodes (AR(+): ISHLT>or=3) were compared to 89 samples from non-rejection episodes (AR(-): ISHLT grade 0, n=52; grade 1, n=29; grade 2, n=8). We observed an inverse correlation of mDCs (P<0.05) but not pDCs with increasing rejection grade. PBDC incidence and mDC/pDC ratio were low in blood samples obtained during AR (P<0.05 and P<0.01, respectively). Both PBDCs and mDC/pDC ratio decreased during each AR episode (P<0.05). Comparison of 3A(+) and 3A(-) rejectors with NR patients after 12 weeks post-HTx revealed lower PBDC incidence (P<0.01) and mDC/pDC ratio (P<0.05) for R patients, independent of rejection therapy. CONCLUSIONS: Defective DC subset reconstitution by dendritic cell profiling identifies patients at risk for AR after 3 months post-HTx. This finding may contribute to further optimization of immunosuppressive treatment strategies after clinical heart transplantation.     

Dendritic Cell Deficiency in the Blood of Kidney Transplant Patients on Long-Term Immunosuppression: Results of a Prospective Matched-Cohort Study

Evidence from in vitro studies suggests that immunosuppressive drugs interfere with key functions of dendritic cells (DCs), but the in vivo relevance of these findings is elusive. We prospectively analyzed the major DC precursor subsets in the blood of kidney transplant recipients on long-term immunosuppression (> or =1 year). A total of 87 patients were compared to 87 age- and sex-matched controls. Total DC numbers and the precursor subsets, myeloid type 1 DCs, myeloid type 2 DCs (mDC1, mDC2) and plasmacytoid DCs (pDCs) were identified by four color flow cytometry. Long-term immunosuppression was associated with significant reduction of all major DC subsets in comparison to healthy controls (mDC1 p < 0.001; mDC2 p < 0.0001; two-tailed Mann-Whitney U-test) with the strongest negative impact on pDCs (p < 0.00001). In contrast, total leukocyte numbers were not significantly affected. Analysis of the relative impact of different agents revealed a significant impact of prednisolone on pDCs (p = 0.009) and mDCs2 (p = 0.006). The functional relevance of pDC deficiency was confirmed independently by Interferon-alpha analysis after Toll-like receptor 7 (p < or = 0.001) and 9 (p < 0.05) stimulation. These results indicate for the first time a profound negative impact of long-term immunosuppression on major DC subsets in kidney transplant recipients. DC deficiency may have important implications with respect to viral infections and tumor development.     

输注转染IL-2基因同源短发夹型RNA的淋巴细胞抑制大鼠肝移植急性排斥反应

目的 探讨输注转染白细胞介素2(IL-2)基因同源短发夹型RNA(shRNA)的受者淋巴细胞对大鼠肝移植后急性排斥反应的影响.方法 构建针对大鼠活化T淋巴细胞IL-2基因编码区的shRNA表达质粒,体外转染受者(BN大鼠)淋巴细胞.以Lewis大鼠为供者、BN大鼠为受者,进行肝移植,干扰组的受者于移植术中经门静脉回输转染IL-2-shRNA的BN大鼠淋巴细胞;环孢素A组(CsA组)的受者移植术中经门静脉输入生理盐水,肝移植后应用CsA肌肉注射;生理盐水对照组的受者移植术中经门静脉输入生理盐水;空载体对照组的受者移植术中经门静脉输入转染空载体的BN大鼠淋巴细胞.术后第7天,处死BN大鼠,取移植肝组织,观察组织和细胞超微结构改变情况以及肝细胞凋亡情况,同时测定肝功能指标、肝组织中IL-2基因的表达以及血清IL-2、肿瘤坏死因子a(TNF-α)和γ干扰素(IFN-γ)水平.计算各组受者1周存活率.结果 移植后第7天,生理盐水对照组和空载体对照组的移植肝组织中可见中、重度急性排斥反应改变,而干扰组和CsA组病理切片中无或仅有轻度急性排斥反应征象.干扰组凋亡肝细胞数为(23±3.2)/mm2,CsA组为(26±4.0)/mm2,均明显低于生理盐水对照组和空载体对照组(P＜0.05).干扰组和CsA组的IL-2mRNA表达明显低于生理盐水对照组和空载体对照组(P＜0.05);干扰组和CsA组的血清IL-2、TNF-α和IFN-γ水平较空载体对照组和生理盐水对照组分别有不同程度降低(P＜0.05).干扰组和CsA组的丙氨酸转氨酶和总胆红素均明显低于空载体对照组和生理盐水对照组(P＜0.05).而白蛋白则高于空载体对照组和生理盐水对照组(P＜0.05).干扰组受者1周存活率为87.5%(7/8),明显高于生理盐水对照组的37.5%(3/8)和空载体对照组的37.5%(3/8,P＜0.05).结论 输注转染IL-2-shRNA的受者淋巴细胞可抑制大鼠肝移植后的急性排斥反应,但这种作用是短期的.     

The effects of renal transplantation on peripheral blood dendritic cells

Recent advances allow accurate quantification of peripheral blood (PB) myeloid and plasmacytoid dendritic cell (DC) populations (mDC and pDC, respectively), although the response to renal transplantation (RT) remains unknown. Using flow cytometry, PBDC levels were quantified in patients with end stage renal disease (ESRD) undergoing RT. PBDC levels were significantly reduced in ESRD patients pre-RT compared to healthy controls, with further reduction noted immediately following a hemodialysis session. RT resulted in a dramatic decrease in both subsets, with a greater reduction of pDC levels. Both subset levels were significantly lower than in control patients undergoing abdominal surgery without RT. Subgroup analysis revealed significantly greater mDC reduction in RT recipients receiving anti-lymphocyte therapy, with preferential binding of antibody preparation to this subset. Samples from later time points revealed a gradual return of PBDC levels back to pre-transplant values concurrent with overall reduction of immunosuppression (IS). Finally, PBDC levels were significantly reduced in patients with BK virus nephropathy compared to recipients with stable graft function, despite lower overall IS. Our findings suggest that PBDC levels reflect the degree of IS in renal allograft recipients. Furthermore, PBDC monitoring may represent a novel strategy to predict important outcomes such as acute rejection, long-term graft loss and infectious complications.     

白细胞介素2-绿脓杆菌外毒素抑制小鼠角膜移植后的排斥反应

目的 观察白细胞介素2-绿脓杆菌外毒素(IL-2-PE40)对小鼠角膜移植排斥反应的抑制作用.方法 以C57BL/6小鼠为供者,Balb/c小鼠为受者,制备小鼠同种异体穿透性角膜移植模型,治疗组受者于手术当天起腹腔注射IL-2-PE40,用量为0.6μg/g,每12 h 1次,直至排斥反应发生;对照组相应时间点腹腔注射等体积生理盐水.术后每周在裂隙灯下观察移植角膜2次,根据Hori等的分级标准,对移植角膜混浊和新生血管进行分级,判断排斥反应发生情况,发生排斥反应时判定为移植角膜存活终止;并在术后第10、15、25、35天分别取术眼,行组织学观察,同时收集外周血,测定T淋巴细胞亚群及T淋巴细胞集落形成数.结果 治疗组与对照组移植角膜存活时间分别为(30.2±2.9)d和(15.1±2.1)d,对照组于术后第15天出现排斥反应;术后对照组CD4~+细胞开始升高,于第15天升高最为明显,达(63.9±4.0)%,随后下降,而治疗组CD4~+细胞仅轻微上升,第15天为(42.6±4.0)%,明显低于对照组(P<0.01);术后2个组CD8~+细胞变化不大;术后对照组T淋巴细胞集落形成数呈先升后降趋势,第15天上升最为明显,为(296±17)个,随后下降,而治疗组的变化不明显,第15天为(201±16)个,明显低于对照组(P<0.01).结论 IL-2-PE40可推迟角膜移植排斥反应的发生时间;能明显减少外周血中辅助性T淋巴细胞的作用,并能减弱小鼠外周血T淋巴细胞集落形成能力.     

输注转染FasL基因的供者树突状细胞减轻小鼠心脏移植排斥反应

目的 探讨转染FasL基因的供者树突状细胞(DC)对小鼠心脏移植排斥反应的影响.方法 分离并培养C57BL/6小鼠骨髓DC,然后采用脂质体法以自行构建的pTracer-FasL真核表达质粒转染DC.以C57BL/6小鼠为供者,Balb/c小鼠为受者,将其分为转染组(n=12)、未转染组(n=12)及移植对照组(n=12).转染组小鼠心脏移植前7 d经阴茎背静脉注射1×106个转染FasL基因的供者DC;未转染组小鼠心脏移植前7 d经阴茎背静脉注射1×106个未转染的供者DC;移植对照组仅行心脏移植,不接受供者DC输注.供心均移植于受者腹腔内.各组中,6只小鼠用于观察移植心脏存活时间,另6只于术后7 d处死,取移植心脏,进行组织学观察及移植心脏排斥反应病理分级.结果 转染组、未转染组和移植对照组小鼠移植心脏存活时间的中位数分别为20 d、8.5 d和9 d,转染组移植心脏的存活时间明显长于未转染组和移植对照组(P＜0.01).转染组中,2只排斥反应的病理分级为0级,4只为1级;未转染组中,2只为2级,4只为3级;移植对照组中,1只为2级,5只为3级.转染组排斥反应的病理分级明显低于移植对照组(P＜0.01).结论 受者于心脏移植前输注转染FasL基因的供者DC,可有效延长移植心脏的存活时间,并减轻排斥反应的程度.     

CTLA4-Ig对肝细胞移植大鼠免疫耐受的作用及其机制

目的 探讨细胞毒性淋巴细胞相关抗原4融合蛋白(CTLA4-Ig)诱导肝细胞移植大鼠免疫耐受的作用及机制.方法 10%D-氨基半乳糖(D-gal)一次性腹腔注射建立大鼠急性药物性肝衰竭模型;采用肝脏原位灌注法分离纯化肝细胞,经脾脏移植后随机分为两组.实验组腹腔一次性注射CTLA4-Ig,对照组不予处理.两组均分别于术后第1、3、5、7天采外周血观察白细胞介素(IL)-2、肿瘤坏死因子(TNF)及肝功能变化;术后1周测两组大鼠外周血T细胞亚群,处死大鼠后取脾脏苏木素-伊红(HE)染色.结果 实验组谷丙转氨酶(ALT)、血清总胆红素(TBil)于术后第7天分别为(6.5±7.3)IU/ml、(5.1±1.6)mmol/L,低于对照组.术后治疗组IL-2含量明显下降,第7天达到(1. 3138±0.8508)ng/L,两组差异有统计学意义(P＜0.05);术后TNF含量两组之间差异无统计学差异(P＞0.05).外周血CD4+T细胞、CD4+/CD8+T细胞实验组分别为(37.3±7.2)%、(1.5±0.1)%,低于对照组(P＜0.05),CD8+T细胞两组差异无统计学意义(P＞0.05).术后第7天治疗组脾内仍可见肝细胞或肝细胞团,对照组见大量淋巴细胞浸润,但很少见肝细胞.结论 CTLA4-Ig能诱导经脾同种异体肝细胞移植大鼠免疫耐受,使急性肝衰大鼠肝功能得到改善.可能是抑制T淋巴细胞亚群,且主要是抑制CD4+T细胞,使CD4+/CD8+T细胞比值下降;抑制IL-2的分泌.

Abstract：

Objective To investigate the immunosuppressive effect of cytotoxic T Iymphocyte associated antigen 4 Ig fusion protein (CTLA4-Ig) in rat allograft hepatocyte transplantation model and the mechanisms. Methods Acute liver failure (ALF) model was established by intraperitoneal injection of 10% D-gal solution to SD rates. Collagenase perfusion was performed on SD rats to separate liver cells. SD rats with ALF were subjected to intrasplenic hepatocyte transplantation and randomly divided into two groups. The experimental group received intraperitoneal injection of CTLA4-Ig. The concentrations of interleukin (IL)-2 and tumor necrosis factor (TNF), liver function and histologicy were observed at the 1st,3rd, 5th, 7th day after operation and the T lymphocyte subsets were detected by using immunohistochemistry at the 7th day after operation. Results The levels of ALT and TBil were respectively (6. 5 ±7.3) IU/ml and (5.1 ± 1.6) mmol/L at the 7th day after operation and significantly decreased after injection of CTLA4-Ig ( P ＜ 0. 01 ). IL-2 concentration in the experimental group was ( 1.3138 ± 0. 8508 ) ng/L at the 7th day after operation and significantly decreased (P ＜0. 05). TNF had no significant difference between two groups after operation ( P ＞ 0. 05 ). T lymphocyte subsets, mainly CD4 + , in the experimental group was significantly decreased as compared with control group ( P ＜ 0. 05 ), so did the CD4 +/CD8 +. Histological changes: At the 7th day after operation, there were some hepatocytes in the spleen of the experimental group. But in the control group, the changes in the spleen were characterized by severe lymphocyte infiltration. There were no hepatocytes both groups. Conclusion CTLA4-Ig can induce rat allogeneic hepatocytes intrasplenic transplantation immune tolerance. It may improve the liver function of rats with ALF.CTLA4-Ig can decrease T lymphocyte subsets, mainly CD4 + and concentrations of IL-2.