FTY720在鼠类异种胰岛移植排斥反应中的作用

目的 在小鼠异种胰岛细胞移植模型上，研究FTY720在控制异种胰岛移植排斥反应中的作用。方法 使用胰管内胶原酶注射和不连续密度梯度纯化法获取大鼠胰岛，建立小鼠肾被膜下移植模型。受体小鼠随机分为3组：对照组，末使用任何免疫抑制药物；实验1组，自移植当日起每日单独喂服FTY720(1.0mg／kg)；实验2组，亦于移植当日起每日联合喂服FTY720(1.0mg／kg)和环孢霉素A(CsA，15mg／kg)，均连续喂饲14d。分别于术后第3，5，7，14天切取移植物，观察并分析排斥反应。结果 对照组和实验1组，植入。肾被膜下的胰岛组织多在1周内完全被排斥，术后第7天胰岛轮廓消失，仅见大量淋巴细胞浸润。实验2组于移植后第7天及第14天肾被膜下仍可见大量完整的胰岛细胞，几乎未见或偶尔可见淋巴细咆浸润。结论 FTY720单独作为免疫抑制剂并不能抑制鼠类异种胰岛移植的排斥反应；联合应用FTY720及CsA则可有效地抑制鼠类异种胰岛移植排斥反应的发生。     

小鼠异种胰岛移植排斥反应研究

目的观察小鼠对肾被膜下异种胰岛移植物的排斥反应规律和免疫病理学特点。方法将大鼠胰岛移植到小鼠肾被膜下,分别于术后当日、第1、2、4、5、6天取出移植物,研究异种胰岛排斥的病理组织学形态特点和过程。结果异种胰岛移植可有功能存活(5.9±1.2)d,在自然情况下,胰岛在术后6d左右完全被排斥,术后4d胰岛形态已不完整,单核细胞浸润明显增多。移植物附近未发现IgG+IgM的免疫沉积。结论异种胰岛的排斥反应是一个以单核细胞浸润为特征的渐进性过程,移植后4~6d达排斥高峰,CD4+T细胞可能在急性细胞性排斥反应中起重要作用,而体液免疫没有或很少参与。     

应用环孢素A治疗异种肝细胞移植的排斥反应

目的　探讨应用环孢素A(CsA)治疗异种肝细胞移植排斥反应的疗效及其排斥机制。方法　将豚鼠肝细胞植入D-氨基半乳糖诱导的肝衰大鼠脾内,分CsA治疗组和单纯移植组。观察2周生存率及脾病理组织学检查;酶联免疫双抗体夹心法(Sandwich-ELISA)测定大鼠血清白细胞介素(IL)-2的浓度。结果　2周生存率比较CsA治疗组（78.6%）与单纯移植组（80.0%）相比差异无显著性(P＞0.05)。应用CsA可减缓炎症细胞浸润。血清IL-2浓度检测正常大鼠为(28.7±7.0)ng/L,移植后各组血清IL-2浓度变化不大,直至移植后第7天,CsA治疗组为(28.5±6.0)ng/L、单纯移植组为(31.5±8.0)ng/L。3组间差异均无显著性(P＞0.05)。结论　在异种肝细胞脾内移植中,细胞免疫发生的较迟和/或较弱。单独应用CsA治疗异种肝细胞脾内移植引发的排斥反应其疗效不佳。     

异种胰岛移植

胰岛移植可以使糖尿病患者血糖稳定并能预防严重并发症,由于人类同种胰岛移植存在着供体不足,大量糖尿病患者因此得不到及时治疗。在实验研究基础上,国内外均进行了异种胰岛移植的临床研究,证实了胰岛移植在血糖控制及延缓并发症的发生发展是有效的,但是异种移植的排斥、长期应用免疫抑制剂的安全性、仍是干扰此项研究的障碍。尽管异种移植面临众多困难,但对供体器官和组织的极大需求促使克服种间移植的组织特异性不断取得进展。     

FK506与来氟米特预防异种胰岛移植排斥反应的效果

目的　探讨FK5 0 6、来氟米特 (Lef)应用预防大鼠对小鼠异种胰岛移植排斥反应的效果。方法　将 10 0 0～ 12 0 0个大鼠胰岛移植于化学诱导的糖尿病小鼠肾被膜下 ,实验分为对照组、FK 5 0 6组、Lef组和FK5 0 6+Lef组 ,研究胰岛有功能存活情况 ,并在移植后第 5天行病理组织学观察排斥反应。结果　FK5 0 6( 2和 4mg·kg-1·d-1)、Lef( 5、10、2 0mg·kg-1·d-1)术后用药 10d ,胰岛存活时间分别为 ( 8.9± 2 .1)、( 12 .5± 0 .7)、( 10 .8± 1.9)、( 15 .8± 2 .4)、( 18.8± 2 .2 )d ,较对照组( 5 .9± 1.2 )d明显延长 (P <0 .0 1)。FK5 0 6+Lef组移植物存活时间 ( 2 1.8± 1.2 )d ,较单纯用药组效果更好 (P <0 .0 1)。病理组织学显示Lef组与FK5 0 6+Lef组细胞浸润明显减少 ,有更多的完整胰岛存留。结论　FK5 0 6与Lef对异种胰岛移植有抗排斥作用 ,且两药联合应用有协同作用。     

猪异种抗原与异种移植排斥反应

异种移植已成为当今器官移植的研究热点。移植后严重的排斥反应仍是阻碍异种移植成功的主要问题，供器官血管内皮细胞上的主要异种抗原与异种移植后的一系列排斥反应关系密切。本文将介绍近几年来对半乳糖α１，３－半乳糖在异种移植排斥反应机理方面的研究及相应防治措施。     

异种移植中的排斥反应及其对策研究进展

随着器官移植技术在临床的广泛应用 ,同种异基因器官供体远不能满足受体的需要 ,异种移植有可能解决这一矛盾。非灵长类动物 ,特别是猪 ,因其易于饲养 ,且器官大小及免疫学、生理学特性与人类有一定的相似性 ,作为最适的异种移植器官供体已日益引起人们的关注[1,2 ] 。但由于人类和猪两种源间存在巨大的抗原差异 ,针对异种移植物的免疫应答比对同种移植物更加强烈。本文现对近年来有关异种移植排斥机制及其防治策略作一简要回顾。一、异种移植排斥机制1.超急性排斥反应 (hyperacuterejection,HAR):HAR以血栓形成、出血及异种移植物破坏为…     

细胞粘附分子与异种移植排斥反应

排斥反应是导致异种移植失败的主要原因。在异种移植排斥中，移植物血管内皮细胞活化是关键，而细胞粘附分子的表达与内皮细胞的活化以及白细胞趋化均关系密切，更成为异种移植排斥反应中不可获缺的重要环节。本文综述了细胞粘附分子的生物学特点、在异种移植排斥反应中的诱导和表达及其在治疗中的研究进展。     

泛素-蛋白酶体制剂在胰岛移植排斥反应中的作用

目的在小鼠胰岛移植模型上,研究泛察-蛋白酶体抑制剂在控制同种异基因移植排斥反应中的作用。方法泛素-蛋白酶体抑制剂用二肽硼酸类似物(DPBA)作代表。测定小鼠被注射DPBA后的血生化变化观察其可能的副作用。建立小鼠胰岛移植模型。受体糖尿病鼠随机分为 3组:实验组,同种异基因移植24 h时后,每天静脉注射处理DPBA持续17 d。对照1组同基因移植;对照2组,同种异基因移植。两对照组移植后不作任何药物处理。结果DPBA对肝脏胰腺轻度毒性,有一过性的肾毒性和较明显的心脏毒性,停药后毒性明显下降。实验组同种异基因移植的移植物平均存活(33．88±24．54)d;对照2组同种异基因移植的移植物平均存活(4．33±2．42)d。两组比较差异有统计学意义(P<0．05)。结论泛素-蛋白酶体抑制剂可以有效地抑制移植排斥反应,可以使用作为新的免疫抑制剂。     

细胞粘附分子与异种移植排斥反应

排斥反应是导致异种移植失败的主要原因。在异种移植排斥中,移植物血管内皮细胞活化是关键,而细胞粘附分子的表达与内皮细胞的活化以及白细胞趋化均关系密切,更成为异种移植排斥反应中不可获缺的重要环节。本文综述了细胞粘附分子的生物学特点、在异种移植排斥反应中的诱导和表达及其在治疗中的研究进展。     

FTY720预防大鼠肾脏缺血再灌注损伤的实验研究

目的:研究新型免疫抑制剂FTY720对大鼠肾脏缺血再灌注损伤(IRI)的预防作用.方法:制备大鼠肾脏IRI模型,从下腔静脉注入不同剂量的FTY720,观察术后第1、2、3、5、7 d血清肌酐值(Scr)和术后第2、7 d外周血淋巴细胞数(PLC)的变化,并在术后第2 d取肾脏作组织学检查观察急性肾小管坏死的情况.结果:FTY720处理组动物术后Scr水平显著低于对照组并呈剂量依赖性;FTY720处理组术后第2 d的PLC显著低于对照组;组织学检查显示FTY720处理组肾脏的缺血性损伤轻于对照组.结论:FTY720可以减少PLC,对大鼠肾脏IRI有预防作用.     

FTY720诱导大鼠心脏移植物长期存活

目的 观察FTY720对大鼠同种异体心脏移植物存活时间的影响。方法 进行SD Wistar大鼠的腹部异位心脏移植，将受者随机分为对照组、甲泼尼龙(MP)组、环孢素A((SsA)组、FTY720组、FTY720与CsA二药联用组和FTY720、CsA及MP三药联用组，各组按分组要求分别于术前3d至术后14d通过灌胃给予FTY720和CsA，术前1d至术后2d腹腔注射给予MP，观察各组动物术后外周血淋巴细胞数量变化和移植物存活时间。结果 FTY720组、二药联用组和三药联用组的大鼠外周血淋巴细胞在给药后3h开始明显下降，停药后开始回升，至停药14d后恢复正常；移植心脏的存活时间，对照组平均为7．8d，CsA组为16．0d，MP组为27．6d，三药联用组为16．8d，而FTY720组和二药联用组分别超过了150d和124d。结论 FTY720可诱导同种异体大鼠心脏移植物长期存活。     

FTY720联合雷帕霉素抗胰腺癌细胞增殖作用的体外研究

目的 探讨FTY720和雷帕霉素联合用药体外抗胰腺癌细胞增殖的相互作用.方法 采用Panc-1和AsPc-1胰腺癌细胞株作为体外研究模型.以不含FTY720或雷帕霉素培养液处理的细胞株为对照组,FTY720单独用药的浓度范围为1～15 μmol/L;雷帕霉素单独用药的浓度范围为0.002～200 μmol/L,联合用药方案采用两组浓度的雷帕霉素联合7组不同浓度的FTY720;或者采用两组浓度的FTY720联合5组不同浓度的雷帕霉素.采用MTT法评估药物对细胞增殖的抑制率,采用双变量相关性分析法统计药物剂量与细胞增殖抑制率之间的相关性.结果 单独用药作用下,FTY720或雷帕霉素用药剂量与胰腺癌细胞增殖的抑制率呈现剂量依赖性（FTY720＋AsPc-1：r=0.887,P=0.000;雷帕霉素＋AsPc-1：r=0.822,P=0.000 ;FTY720＋Panc-1：r=0.796,P=0.000;雷帕霉素＋Panc-1：r=0.786,P=0.000）.当10μmol/L FTY720和0.002 μmol/L雷帕霉素联用时,对AsPc-1细胞增殖的抑制率达50%（P=0.000）,对Panc-1细胞增殖的抑制率达40%（P=0.000）,两药联用具有协同作用.结论 FTY720及雷帕霉素在体外均能呈剂量依赖性地抑制胰腺癌细胞增殖,联合用药后能协同抑制胰腺癌细胞的增殖.     

FTY720介导淋巴细胞凋亡抑制小肠移植的移植物抗宿主免疫反应

目的 探讨免疫调节药物FTY720对小肠移植后急性移植物抗宿主病（GVHD）的治疗效果及其作用机制.方法 应用Wistar-Furth（WF）大鼠作为供体,WF和ACI大鼠的子代（F1）作为受体,同种异基因异位全小肠移植的技术方法建立GVHD的动物模型.移植受体分为实验组和对照组,每组6只.实验组从移植手术当日开始予以FTY720治疗,持续14 d;对照组在相同的时间段口服蒸馏水.术后第15天,提取受体靶器官肝脏、小肠及移植物小肠的淋巴细胞,应用免疫组织化学（免疫组化）TUNEL法和流式细胞仪检测两组淋巴细胞凋亡的变化.结果 对照组大鼠术后均死亡于GVHD,平均生存时间（16.0±1.7）d,实验组大鼠均长期成活超过100 d,两组差异具有统计学意义（P＜0.01）.免疫组化TUNEL法检测结果显示,实验组肝脏和移植物小肠黏膜的淋巴细胞凋亡比率均明显高于对照组,差异具有统计学意义（P＜0.05）.流式细胞技术分析结果显示,实验组大鼠移植物小肠黏膜内凋亡的淋巴细胞百分比为19.4%,明显高于对照组的11.8%（P＜0.05）;而肝脏凋亡的淋巴细胞百分比两组差异无统计学意义（P＞0.05）.结论 FTY720可能通过诱导淋巴细胞的凋亡,减少和抑制GVHD对靶器官的损害,改善移植大鼠的预后.     

FTY720对大鼠肾小球硬化的作用及机制探讨

目的观察FTY720对5／6肾切除大鼠肾小球硬化的作用并探讨其作用机制。方法选择SD雄性大鼠24只，将其分为假手术组、模型组和FTY720治疗组，每组8只。后两组制作5／6肾切除肾小球硬化模型。末次手术后治疗组给予FTY720灌胃。术前、术后第8、12周取大鼠尾静脉血，采用计数板计算外周血淋巴细胞总数；第12周末处死大鼠后做常规病理检查和免疫组化检测，观察FTY720对肾小球中增殖细胞核抗原（PNCA）、p27、CD3表达的影响。结果治疗组外周血淋巴细胞计数较肾硬化组明显减少。治疗组大鼠肾小球病理损害明显减轻。免疫组化显示，与肾硬化组相比，治疗组PCNA表达明显减弱，p27蛋白表达升高。结论FTY720能减少肾小球内淋巴细胞浸润、上调p27蛋白、下调PCNA的表达，减轻肾小球细胞增殖，延缓肾小球硬化的进展。     

Prevention of graft rejection and graft-versus-host reaction by a novel immunosuppressant, FTY 720, in rat small bowel transplantation

In the present study, we examined the immunosuppressive effect of a new drug, FTY 720, on small bowel transplantation (SBT) in rats. Grafts from (LEW × BN) F 1-to-LEW rats treated with FTY 720 at 0.5 mg/kg from day 0 to 14 post-SBT survived significantly longer than untreated grafts. In addition, the administration of FTY 720 combined with cyclosporin (CyA; 5 mg/kg per day) had a synergistic effect on allograft survival. The graft-versus-host reaction (GVHR) that occurred in the LEW-to-F 1 rats was markedly reduced after the administration of FTY 720. FTY 720 combined with a low dose of CyA completely abrogated GVHR without any adverse reaction. FTY 720 treatment resulted in a significant decrease in the number of lymphocytes in the peripheral blood and the spleen, but the number of peripheral neutrophils was unchanged. Thus, FTY 720 would appear to be an ideal drug to combine with CyA in order to control the immune reaction after SBT. Received: 19 February 1997 Received after revision: 23 May 1997 Accepted: 9 June 1997     

An immunosuppressive regimen using FTY720 combined with cyclosporin in canine kidney transplantation

FTY720 induces apoptosis, specifically in lymphocytes, and prolongs allograft survival in rats and dogs. The purpose of this study was to define an effective range of FTY720 doses that could be combined with a suboptimal dose (10 mg/kg) of cyclosporin for canine kidney allograft recipients. The combination significantly prolonged allograft survival in all groups receiving FTY720 at a dose of 0.1, 0.3, 1.0, or 3.0 mg/kg. None of the recipients died due to notable side effects of the drug. In peripheral blood, the number of lymphocytes was extremely low, whereas the percentage of granulocytes increased during FTY720 administration. No significant difference in cyclosporin trough levels was observed between the cyclosporin-alone group and the combination groups. We conclude from the present study that FTY720 has a potent effect at an extremely low dose and a wide therapeutic window when combined with cyclosporin in canine kidney transplants. Received: 16 May 1997 Received after revision: 6 October 1997 Accepted: 19 November 1997     

Evidence that FTY720 induces rat thymocyte apoptosis

FTY720, a novel immunomodulator with the potential to improve immunosuppressive therapy after organ transplantation, is currently under clinical investigation. FTY720 drastically decreases blood lymphocytes, especially T cells, accelerating lymphocyte homing to secondary lymphoid organs. However, its immunosuppressive effects remain unknown. We investigated these effects in rat thymocytes. Rats were intramuscularly injected with 10mg/kg/day FTY720 or saline for 7days. Thymuses were removed on days 0, 1, 3, 5, 7 and 14 after treatment. Three-color analysis was performed with a flow cytofluorometer. Apoptotic nuclei in the tissue sections were identified by TUNEL. Genomic DNA was then extracted and samples were electrophoresed on 2.0% agarose gel. FTY720 reduced the total number of thymocytes and, with time, significantly reduced the percentage of CD4+8+ TCRalphabeta(negative/low) thymocytes. Light microscopy of thymuses of FTY720-treated rats revealed obvious reductions in the size of the cortical region. TUNEL analysis showed that FTY720 induced thymocyte apoptosis in the cortical region. Furthermore, DNA fragmentation was observed in thymocytes treated with FTY720, indicating thymocyte apoptosis. FTY720 reduced the number of CD4+8+ thymocytes before TCRalphabeta expression resulting in impaired thymocyte differentiation and maturation. This might be an immunosuppressive effect of FTY720.     

FTY720 attenuates tubulointerstitial inflammation and fibrosis in subtotally nephrectomized rats

Abstract

Tubulointerstitial fibrosis is a common pathway that leads to kidney failure, and persistent tubulointerstitial inflammation is a key event in the development of tubulointerstitial fibrosis. The new immunosuppressive drug FTY720 modifies lymphocyte migration into injured tissues by sequestering lymphocytes within secondary lymphoid organs. However, its therapeutic effect on tubulointerstitial inflammation and fibrosis had not been well understood. This study was designed to explore the effect of FTY720 on tubulointerstitial inflammation and fibrosis in subtotally nephrectomized (SNX) rats. In total, 24 male Sprague–Dawley rats were used. Seven days after 5/6 nephrectomy, rats were randomized to FTY720 (1?mg/kg/d) and placebo-treated groups. Sham-operated rats served as controls. FTY720 significantly attenuated the rise in proteinuria, serum creatinine, urea nitrogen and N-acetyl-β-D-glucosaminidase activity in SNX rats, and reduced the count of peripheral white blood cells and lymphocytes in SNX rats. Morphological analysis revealed that there was severe tubulointerstitial inflammation and fibrosis in SNX group and much more tubulointerstitial infiltrating inflammatory cells with high expression of CD3, CD4, CD8, CD20, CD68, CD163 and CCR-7 in SNX group, as compared with the controls, but the lesions were attenuated significantly by treatment with FTY720. Furthermore, the expressions of proinflammatory molecules (IL-6, TNF-α and MCP-1), profibrotic molecule (TGF-β1) and production of extracellular matrix proteins such as fibronectin and types I and III collagens were upregulated in SNX rats. FTY720 administration significantly reduced these abnormalities. In summary, FTY720 exerts therapeutic effects on tubulointerstitial fibrosis in SNX rats by inhibiting the tubulointerstitial inflammatory response.