大鼠胰岛转染人血红素氧合酶-1基因对同种胰岛移植的影响

目的探讨大鼠胰岛转染人血红素氧合酶-1(HO-1)基因在胰岛移植中的潜在应用价值。方法采用携带人HO-1基因的腺病毒对新分离的SD大鼠胰岛细胞进行转染;对体外培养的胰岛细胞使用重组人肿瘤坏死因子α及放线菌酮诱导凋亡。使用流式细胞术检测凋亡率;每只链脲霉素诱导的糖尿病模型大鼠门静脉内置入约1200个胰岛当量的胰岛后,观察糖尿病大鼠血糖及体重变化;免疫组织化学法检测肝内移植胰岛细胞的胰岛素、HO-1蛋白表达及表达CD3抗原的淋巴细胞浸润情况。结果转染人HO-1基因的胰岛细胞凋亡率明显低于对照组(P<0.05);单纯胰岛细胞移植后移植物存活时间为(5.33±4.18)d,转染人HO-1基因的胰岛细胞移植后移植物存活时间为(10.56±4.33)d,两组比较,P<0.05;转染人HO-1基因的胰岛细胞培养48 h即见人HO-1蛋白表达;肝内移植7 d后移植物有人HO-1蛋白表达;移植胰岛周边及胰岛内淋巴细胞浸润程度较单纯胰岛移植组明显减轻。结论大鼠胰岛转染人HO-1基因能够增加体外培养胰岛细胞的抗凋亡能力,并能延长体内移植胰岛的存活时间,减轻淋巴细胞对胰岛的浸润。     

输注胰岛抗原特异性Treg细胞延长同系NOD小鼠移植胰岛的存活时间

目的 探讨输注胰岛抗原特异性调节性T淋巴细胞(Treg细胞)对非肥胖糖尿病(NOD)小鼠同系胰岛移植物存活时间的影响.方法·以未成熟树突状细胞(imDC)联合谷氨酸脱羧酶-65在体外诱导童贞T淋巴细胞分化成胰岛抗原特异性Treg细胞.以已发生糖尿病的NOD小鼠为受者,将分离得到的尚未进展为糖尿病的NOD小鼠的胰岛(500胰岛当量)移植至受者的肾包膜下,对照组不行移植,只观察血糖变化;单纯胰岛移植组只进行胰岛移植,不输注胰岛抗原特异性Treg细胞;实验组于术前1d静脉输注1×106个胰岛抗原特异性Treg细胞,然后进行胰岛移植.术后检测受者的血糖,以判断移植胰岛的存活时间,观察胰岛移植物的病理学变化.结果 对照组血糖持续高于11.1 mmol/L;单纯胰岛移植组小鼠的血糖于术后1～2 d降至正常,到7～17d时开始陆续升高,并维持在术前水平,移植物存活时间为(12.2±2.6)d;实验组小鼠的血糖于术后1～2 d降至正常,至第27天开始有小鼠血糖升高超过11.1 mmol/L,第43天时,所有小鼠的血糖均超过11.1mmol/L,移植物的存活时间为(35.2±4.3)d,明显长于单纯胰岛移植组(P＜0.01).单纯胰岛移植组的移植胰岛有明显的淋巴细胞浸润,并伴有胰岛细胞严重破坏,胰岛素染色未见完整的胰岛存在,仅有极少量残存的分泌胰岛素的胰岛细胞;实验组第15天时移植胰岛形态完整,仅有少量淋巴细胞浸润,分泌胰岛素的胰岛大量存在.结论 体外诱导产生的胰岛抗原特异性Treg细胞可以延缓自身免疫系统对移植胰岛的破坏,明显延长NOD小鼠移植胰岛的存活时间.     

诱导供者胰岛细胞高表达血红素加氧酶-1延长大鼠胰岛移植物的存活时间

目的 探讨钴原卟啉(CoPP)诱导大鼠胰岛细胞高表达血红素加氧酚1(HO-1)后,对延长胰岛移植物存活时间的作用.方法 (1)将分离和纯化的供者(BN大鼠)胰岛细胞分为CoPP诱导组和未诱导组.CoPP诱导组供者在分离胰岛细胞前3天和前1天腹腔注射2.5 mg/kg的CoPP,未诱导组不注射CoPP.诱导后,采用免疫荧光法及Western免疫印迹法检测两组胰岛细胞中HO-1的表达情况,采用酶联免疫吸附试验(ELISA)和葡萄糖刺激试验检测胰岛细胞的胰岛素释放水平.(2)Lewis大鼠经四氧嘧啶静脉注射后建立糖尿病模型,取10只成功建立糖尿病模型的大鼠作为胰岛细胞移植的受者,随机平均将受者分为实验组和对照组,分别移植经CoPP诱导和未经诱导的供者胰岛细胞.移植后,观察和比较两组受者胰岛移植物的存活时间和发生排斥反应后胰岛移植物的组织病理学变化.结果 CoPP诱导组胰岛细胞高表达HO-1,而未诱导组不表达HO-1;CoPP诱导组和未诱导组供者胰岛细胞胰岛素分泌量,在低糖刺激下分别为(15.65±0.89)mU/L和(12.28±0.89)mU/L(P>0.05),在高糖刺激下分别为(46.60±1.13)mU/L和(19.01±1.49)mU/L(P<0.05),刺激指数分别为2.98±0.10和1.55±0.01(P<0.05).实验组和对照组胰岛移植物平均存活时间分别为(12.20±5.67)d和(5.60±1.14)d(P<0.05);当受者发牛排斥反应时,对照组胰岛移植物周边可见明显的淋巴细胞、成纤维细胞以及单个核细胞浸润,而实验组细胞浸润的程度明显较轻.结论 CoPP可诱导大鼠胰岛细胞高表达HO-1,其对胰岛细胞有明显保护作用.移植高表达HO-1的胰岛细胞能显著延长胰岛移植物的存活时间.     

免疫缺陷树突状细胞诱导异种胰岛细胞移植耐受

目的　研究受体来源免疫缺陷树突状细胞(dendriticcell, DC)诱导异种胰岛细胞移植的免疫耐受作用及其机制。方法　从BALB/C小鼠骨髓干细胞诱导分化免疫缺陷DC,负载Wistar大鼠MHC抗原。将上述DC通过尾静脉回输糖尿病小鼠体内(预处理组), 7d后分别将Wistar或SD大鼠胰岛细胞移植于受体鼠肾包膜下。观察移植物存活时间,检测T细胞增殖及TH1 /TH2细胞因子的表达。结果　与对照组相比,预处理组胰岛细胞存活时间明显延长(P < 0. 0 5 ),而以SD大鼠胰岛细胞作为供体的移植物存活时间无明显改变。免疫缺陷DC预处理受体鼠T细胞增殖反应微弱,且TH1 /TH2细胞因子表达明显下降。结论　负载异种MHC抗原的免疫缺陷型DC预处理受体可诱导抗原特异性T细胞无能,以及TH1 /TH2细胞因子的低表达,从而有效地延长异种胰岛细胞存活时间。     

胰岛FasL基因转染对大鼠胰岛移植的影响

目的 探究胰岛细胞FasL基因转染对同种大鼠胰岛移植的影响。方法 通过磷酸钙沉淀法构建含目的基因FasL的重组腺病毒AdV-FasL,感染胰岛细胞后移植于糖尿病受者大鼠,通过RT-PCR和免疫组织化学检测移植物FasL表达,观察移植物存活情况及基因转染胰岛细胞凋亡情况。结果 单纯移植胰岛组平均存活期为（6.3±0.56）d,FasL基因转染组并未出现排斥延迟,反而排斥加速,存活期缩短至（3.4±0.24）d。FasL转染的胰岛细胞在移植后24h见FasL表达,在 48 h表达增强,AdV-5感染组及未转染组未见FasL表达。TUNEL标记见移植后FasL转染胰岛细胞凋亡。结论 尽管表达FasL的睾丸细胞与胰岛共移植可诱导活化的淋巴细胞凋亡,使胰岛移植物获得免疫豁免、存活期延长,但通过FasL基因转染使胰岛细胞直接表达FasL,引起胰岛细胞凋亡和粒细胞浸润,导致排斥加速。     

Fas配体表达诱导同种胰岛移植免疫豁免

目的　探究睾丸细胞FasL表达能否对同时移植的胰岛移植物提供免疫豁免作用。方法　将不同数量的同种大鼠睾丸细胞与1500个胰岛同时移植于糖尿病受体,观察移植物功能、存活情况,以及移植物内淋巴细胞凋亡情况,并体外检测睾丸Sertoli细胞对活化淋巴细胞的抑制作用。结果　单纯移植胰岛组平均存活期为(5.0±0.5)d。睾丸细胞和胰岛细胞同时移植,当睾丸细胞数为5×106个,平均存活期为(10.0±0.6)d;增加移植睾丸细胞数至1×107个时,存活期大于50d（P＜0.05）。表达FasL的睾丸细胞在移植物内诱导浸润淋巴细胞凋亡,体外抑制淋巴细胞活性。结论　表达FasL的睾丸细胞可诱导浸润的活化淋巴细胞凋亡,使同时移植胰岛移植物获得局部免疫豁免、存活期延长。     

Fas配体表达对同种胰岛移植的影响

目的探究睾丸细胞FasL表达能否对共移植的胰岛移植物提供免疫豁免作用以及胰岛细胞FasL基因转染对同种胰岛移植的影响.方法将同种大鼠胰岛及睾丸细胞同时移植于糖尿病受体,重组腺病毒AdV-FasL感染胰岛细胞后移植,观察移植物存活情况、胰岛功能,并检测移植物内浸润淋巴细胞以及基因转染胰岛细胞凋亡情况.结果单纯移植胰岛组平均存活期为(6.3±0.56)?d.与胰岛细胞同时移植的睾丸细胞数增加至1×107时,存活期大于50?d(P＜0.05).表达FasL的睾丸细胞在移植物内诱导浸润淋巴细胞凋亡.FasL基因转染组出现排斥加速,存活期缩短至(3.4±0.24)?d.FasL转染的胰岛细胞在移植后24h见FasL表达,48h表达增强,移植后FasL转染胰岛细胞凋亡.结论表达FasL的睾丸细胞与胰岛同时移植可诱导活化的淋巴细胞凋亡,使胰岛移植物获得免疫豁免、存活期延长,但通过FasL基因转染使胰岛细胞直接表达FasL引起胰岛细胞凋亡和粒细胞浸润,导致排斥加速.     

Sertoli细胞诱导大鼠肝内胰岛移植物免疫豁免的实验研究

目的 探究睾丸Sertoli细胞能否对肝内共移植的胰岛移植物提供免疫豁免作用以及共移植的睾丸Sertoli细胞最佳数量。方法将同种大鼠胰岛及不同数量的睾丸Sertoli细胞同时移植于糖尿病受体的肝内,观察移植物存活情况、胰岛功能、并检测移植物内胰岛素和Fas配体(FasL)表达以及浸润淋巴细胞凋亡情况。结果单纯胰岛移植组平均存活期为(5.6±0.8)d,同时与胰岛细胞在肝内共移植的睾丸细胞数增加至1×107个时,平均存活期为(41.4±4.61)d,明显延长(P<0.05),胰岛移植物中有大量表达FasL的睾丸细胞和表达胰岛素的胰岛细胞.在移植物周围有大量浸润的淋巴细胞凋亡。结论睾丸Sertoli细胞与胰岛细胞同时在肝内共移植,通过诱导局部豁免而延长胰岛移植物的存活时间,且同时共移植1×107个Sertoli细胞时效果最好。     

脂肪间充质干细胞与胰岛联合移植对术后免疫状态及移植效果的影响

目的研究同系脂肪间充质干细胞(AMSC)与同种异体胰岛联合移植对胰岛移植术后免疫状态及移植效果的影响。 方法选择Lewis大鼠建立链脲佐菌素诱导的糖尿病大鼠模型作为胰岛移植受体,AMSC＋胰岛移植组经左肾包膜下联合移植Lewis大鼠AMSC及Wistar大鼠胰岛,单纯胰岛移植组经左肾包膜下单独移植Wistar大鼠胰岛,单纯AMSC移植组经左肾包膜下单独移植Lewis大鼠AMSC,阳性对照组为未进行移植的Lewis糖尿病大鼠,阴性对照组为正常Lewis大鼠。ELISA法检测血清细胞因子IFN-γ、IL-2、IL-4和IL-10浓度,流式细胞技术检测外周血CD4^＋、CD8^＋ T细胞比例,HE染色观察移植胰岛淋巴细胞浸润情况,观察血糖、胰岛素水平及胰岛移植物存活时间。采用单因素方差分析比较5组大鼠外周血淋巴细胞亚群比例和血清细胞因子水平,采用LSD法进行组间两两比较;血糖及血清胰岛素变化采用重复测量资料方差分析;采用独立样本t检验比较AMSC＋胰岛移植组与单纯胰岛移植组胰岛移植物淋巴细胞计数。采用Kaplan-Meier法绘制AMSC＋胰岛移植组与单纯胰岛移植组胰岛移植物生存曲线,并采用log-rank检验进行比较。P<0.05为差异有统计学意义。 结果AMSC＋胰岛移植组胰岛移植物平均生存时间为(26.8±3.0) d,长于单纯胰岛移植组的(19.0±1.3) d,两组大鼠胰岛移植物生存曲线差异有统计学意义(χ²＝4.494,P<0.05)。胰岛移植后各时间点,AMSC＋胰岛移植组大鼠移植后血糖和胰岛素水平均优于单纯胰岛移植组(P均<0.05)。胰岛移植前,5组大鼠外周血CD4^＋、CD8^＋ T细胞比例以及细胞因子IFN-γ、IL-2、IL-4和IL-10差异均无统计学意义(F＝0.425、0.476、0.256、0.418、0.281和0.313,P均>0.05)。胰岛移植后第7、14、28天,AMSC＋胰岛移植组大鼠外周血CD4^＋、CD8^＋T细胞比例均低于单纯胰岛移植组(P均<0.05),血清IFN-γ和IL-2浓度均低于单纯胰岛移植组(P均<0.05),IL-4和IL-10浓度均高于单纯胰岛移植组(P均<0.05)。胰岛移植第7天,AMSC＋胰岛移植组胰岛移植物平均淋巴细胞计数为(142±21)个/mm²,低于单纯胰岛移植组的(311±36)个/mm²(t＝8.245,P<0.05)。 结论与胰岛联合移植的AMSC能够提高胰岛移植的效果,可调节糖尿病大鼠体内IFN-γ、IL-2、IL-4和IL-10表达及抑制同种异体胰岛刺激的T细胞增殖,减轻胰岛移植物的免疫损伤。     

激活型Akt1转染大鼠胰岛联合应用细胞毒T淋巴细胞相关抗原4免疫球蛋白延长异种胰岛移植存活

目的 观察激活型Akt1基因转染大鼠胰岛对异种胰岛移植功能和存活的影响.方法 提取大鼠胰岛培养转染,AO/EB和Tunel染色检测存活和凋亡;BALB/C糖尿病小鼠肾被膜下胰岛移植.分4组,实验组:Akt1转染胰岛联合应用细胞毒T淋巴细胞相关抗原4免疫球蛋白(CTLA-4Ig);Akt1组:移植Akt1转染的胰岛;未转染组:单纯胰岛移植,CTLA-4Ig组:单纯胰岛联合应用CTLA-4Ig;观察胰岛移植后功能存活时间和平均生存时间.结果 Akt1转染胰岛体外细胞抗凋亡生存率提高了25%;实验组移植物功能存活(32.5±6.6)d,平均生存时间(39.6±5.9)d比Akt1组(15.4±3.5)、(22.5±1.7)d和CTLA-4Ig组(18.7±4.5)、(21.7±3.5)d未转染组(4.5±2.8)、(6.8±3.1)d明显延长(P<0.05).结论 激活型Akt1转染大鼠胰岛联合应用CTLA-4Ig,可减少移植胰岛凋亡,延长异种胰岛移植物存活时间.     

肝星状细胞对同种异体胰岛移植物的保护作用

目的 研究小鼠肝星状细胞对同种异体胰岛移植物的保护作用.方法 将糖尿病小鼠随机分为三组,分别为糖尿病组、单纯胰岛移植组及与肝星状细胞共同移植组.单纯移植组于肾被膜下移植入同种异体胰岛300个;共同移植组移植入肝星状细胞(3×105个)与同种异体胰岛(300个)混合物.分别于移植术后监测受体小鼠血糖值及正常血糖维持时间;血糖正常一周后移植组及糖尿病组小鼠分别采血检测血清中TGF-β,TNF-α,IL-1β,IFN-γ的含量,同时取出移植物进行免疫组织化学检测.结果 术后共同移植组受体正常血糖维持时间为(23.75±8.96)d,单纯胰岛移植组受体正常血糖维持时间为(11.9±6.92)d,差异有统计学意义(P<0.05);三组受体血清中TNF-α、IL-1β、IFN-γ含量差异无统计学意义(P>0.05),共同移植组受体血清中TGF-β含量为(2292.31±5.87)pg/ml,单纯移植组为(1246.55±38.91)pg/ml,两组比较差异有统计学意义(P<0.05);病理学结果显示共同移植组胰岛素表达量大,并且在移植物周围有生物包膜形成.结论 在同种异体移植模型中,肝星状细胞可能通过高分泌TGF-β、局部形成包囊等方式保护胰岛移植物并延长其存活时间.     

Development of an immunoprivileged site to prolong islet allograft survival

Sertoli cells (SC) play a critical role in the maintenance of the immunoprivileged environment of the testis. We hypothesized that preengrafting SC would allow one to develop a vascularized immunoprivileged ectopic site that provides protection for mouse islet allografts. SC, prepared from 9-day Balb/c mice, were transplanted under the kidney capsule in adult Balb/c mice. After SC engraftment (approximately 30 days), mice were rendered diabetic and subsequently implanted with Balb/c or CBA/J islets directly adjacent to the established SC grafts. Preengrafted SC (5.7 +/- 0.2 x 106) had no adverse effect on syngeneic islet graft function. When allogeneic islets were transplanted into the immunoprivileged ectopic site created by preengrafting 6.4 +/- 0.3 x 10(6) SC, mean graft survival was slightly prolonged (32.4 +/- 6.0 days) compared with control mice that received allogeneic islets alone (16.3 +/- 1.5 days; p = 0.329). In contrast, when 4.8 +/- 0.4 x 10(6) SC were preengrafted, islet allograft survival was significantly prolonged (66.1 +/- 9.8 days; p = 0.001). Four of eight mice, preimplanted with 4.8 +/- 0.4 x 10(6) SC, remained normoglycemic throughout the follow-up period (83.8 +/- 8.6 days) and returned to a diabetic state only when the kidneys bearing the composite grafts were removed. Transplantation of islets into an immunoprivileged ectopic site created by preengrafting SC did not affect islet function and, moreover, provided a means of developing an immunopriveliged ectopic site that permits prolonged islet allograft survival without systemic immunosuppression.     

CTLA4Ig基因对大鼠胰岛移植后排斥反应的治疗作用

目的　研究CTLA4Ig基因在糖尿病大鼠体内表达及其产物对胰岛移植物存活的作用。方法　利用Lipofectin载体包裹CTLA4IgcDNA质粒后转染鼠胰岛和肌肉细胞 ,检测移植后CT LA4Ig表达和T淋巴细胞转化率。结果　胰岛移植术后 7dT淋巴细胞转化试验 ,实验组 (A组 )和对照组 (B组 )每分钟脉冲数 (cpm)分别为175 .7± 98.2 ,2 5 4.4± 116 .3 ,两组比较差异显著 (P <0 .0 5 )。A组胰岛移植第 7d ,2只大鼠血清CTLA4Ig呈阳性 (阳性率 2 0 % )。A、B两组胰岛移植后血糖维持正常时间分别为 (14.8± 12 .3)d和 (3 .6± 5 .1)d ,两组比较差异显著 (P <0 .0 5 )。A、B两组大鼠平均存活时间分别为 (2 4.0± 10 .8)d和 (10 .8± 4.8)d ,两组比较 ,差异有极显著性 (P <0 .0 1)。结论　脂质体包裹的CTLA4IgcDNA转染肌细胞和胰岛细胞 ,可以在受体大鼠胰岛细胞或肌肉组织中表达 ,其表达产物可使胰岛移植物和受体鼠存活时间明显延长 ,抑制细胞免疫活性 ,发挥其治疗排斥反应的作用     

B7-H4 induces donor-specific tolerance in mouse islet allografts

Negative cosignaling molecules play an important role in regulating T-cell responses to alloantigen stimulation. We recently reported that adenoviral-mediated transduction of islet allografts with B7-H4 inhibits allograft rejection. In this study, we investigate the mechanism for B7-H4-induced prolongation of mouse islet allograft survival. Streptozotocin-induced diabetic C57BL/6 mice were rendered normoglycemic by renal subcapsular implants of B7-H4-transduced BALB/c islets. Grafts and spleens were removed after days 2, 10, and 60 (n = 8 each) for characterization of kinetics of Foxp3 and interleukin 10 (IL-10) expression. Mixed lymphocyte reaction (MLR) was done at day 60. Ten mice were subjected to nephrectomy at 60 days and then five were implanted with secondary BALB/c islets and five were given third-party CBA/J islets. An increase in Foxp3 and IL-10 mRNA expression was detected in recipients' spleens at day 60 and this was associated with increased quantities of Foxp3(+) cells. Splenocytes at day 60 showed hyporesponsiveness during MLR to alloantigen stimulation. Proliferation was partially restored after CD25(+) T-cell depletion. Secondary BALB/c islets survived for 79 ± 29 days compared with 21 ± 3.6 days for CBA/J islets (p < 0.001). Local expression of B7-H4 induces long-term unresponsiveness to donor-specific alloantigens, and is associated with T regulatory cells, suggesting the development of tolerance.     

Immunomodulation by adenoviral-mediated SCD40-Ig gene therapy for mouse allogeneic islet transplantation

BACKGROUND: The success of pancreatic islet transplantation is limited because of immune rejection of allogeneic transplanted tissue and potential adverse side effects of nonspecific immunosuppression. Local expression of an immunosuppressive agent at the site of islet transplant could promote long-term engraftment without associated systemic side effects. METHODS: We have examined the ability of adenoviral vector mediated local production of sCD40-immunoglobulin (Ig), blocking the CD40-CD40 ligand (CD40L) costimulatory pathway, from genetically modified allogeneic islets to facilitate long-term engraftment in fully allogeneic mouse model. RESULTS: Transplantation of islets infected with an adenoviral vector expressing sCD40-Ig resulted in allograft survival longer than 120 days in five of the nine recipient mice (56%). However, mice that received mock infected (n=5) or control adenoviral vector (Ad.eGFP; n=6) rejected the allograft with a median survival of 15 and 16 days, respectively. Histopathology demonstrated that the grafts of the long-term surviving animals preserved islets with minimal mononuclear cell infiltration. CONCLUSION: These results demonstrate that local inhibition of the CD40-CD40L pathway by adenoviral gene transfer of sCD40-Ig to the islets prior to transplant significantly prolonged islet allograft acceptance. This approach could be used clinically to facilitate islet transplantation.     

Effect of anti-Ia antibodies, culture, and cyclosporin on prolongation of canine islet allograft survival

Evidence in rodents suggests that islet pretreatment to reduce islet immunogenicity will also require some form of immunosuppression of the recipient for islet allograft acceptance in highly reactive donor-recipient pairs. We attempted to ascertain whether outbred dogs would also require treatment of both donor islets and the recipient to prolong islet allograft survival. Untreated canine islets are uniformly rejected in 6-10 days in beagles. Tissue culture alone, at 37 degrees C for 7 days, or treatment of freshly prepared islets with anti-Ia monoclonal antibodies (MoAbs) (B1F6 + 7.2) did not prolong canine islet allograft survival. Treatment of culture-maintained canine islets with anti-Ia MoAbs plus complement resulted in prolongation of islet allograft survival for 188 and 368 days in two of seven pancreatectomized nonimmunosuppressed beagles. The administration of low doses of cyclosporin A (CsA) intramuscularly, to recipients of untreated canine islet allografts had no effect on graft survival. By contrast, six of nine CsA-treated recipients of islets that were also treated with anti-Ia MoAbs (B1F6 + 7.2) plus complement showed prolongation of graft survival. Euglycemia was sustained for 19, 34, 89, and 300 days after the CsA was discontinued (day 30) in four of these animals. Two animals had unstable grafts from the beginning that failed 23 and 29 days after transplantation. Our results indicate that simple maneuvers like short-term tissue culture at 37 degrees C and treatment of freshly isolated islets with anti-Ia MoAbs and complement are inadequate to prevent rejection in outbred pancreatectomized beagles.(ABSTRACT TRUNCATED AT 250 WORDS)     

输注供者抗原特异性调节性T淋巴细胞延长小鼠胰岛移植物的存活时间

目的 研究体外扩增获得的供者抗原特异性调节性T淋巴细胞(Treg细胞)对小鼠同种胰岛移植物存活时间的影响.方法 建立从Balb/c小鼠到C57小鼠的胰岛移植模型,通过观察移植后小鼠血糖情况来判断移植胰岛的存活时间.受鼠制成糖尿病模型后分为3组.对照组:不给予任何处理,只观察血糖变化;单纯胰岛移植组:移植胰岛,但不输注Treg细胞;实验组:术前1 d静脉给予1×106个供者特异性Treg细胞,然后行胰岛移植.结果胰岛移植后,对照组小鼠血糖持续高于16.7 mmol/L;单纯胰岛移植组小鼠血糖于术后1～2 d全部降至正常,到7～11 d时陆续开始升高,并维持在术前水平,存活时间为(8.50±1.6)d;实验组小鼠血糖于术后2 d内降至正常,之后维持在较低水平,至第21天开始有小鼠血糖升高超过16.7 mmol/L,存活时间为(26.2±3.9)d,明显长于单纯胰岛移植组(P＜0.05).结论 输注供者抗原特异性Treg细胞可以明显延长移植胰岛的存活时间,在胰岛移植耐受中有积极的作用.

Abstract：

Objective To investigate the effects of donor-specific regulatory T cells (Treg) transfusion on islet allograft survival. Methods Allogeneic fresh islets from Balb/c mice were transplanted to streptozotocin-induced diabetic C57 mice. The survival of islet allografts was observed. The experiment was divided into 3 groups: control group, nothing had been done to the recipients; simple islet transplantation group, the recipients received the islet transplantation only; experimental group, the recipients were given 1 ×106 Treg, then received islet transplantation. Results Blood glucose (BG) was above 16. 7 mmol/L after islet transplantation in control group; In simple islet transplantation group,BG level returned to normal level 1 to 2 days after transplantation, and hyperglycemia appeared 7 to 11 days after transplantation and maintained as the same as that before transplantation; In experimental group, BG level returned to normal level 2 days after transplantation and maintained at a low level,and at the 21st day after transplantation BG level was over 16. 7mmol/L in some recipients. Islet allograft survival in experimental group was significantly prolonged as compared with simple islet transplantation group. Conclusion Donor-specific Treg transfusion could prolong the islet allograft survival,and maybe have positive effect on tolerance induction of islet transplantation.