CTLA4Ig基因在糖尿病大鼠胰岛移植中的作用

为探讨融合蛋白（ＣＴＬＡ４Ｉｇ） 基因在糖尿病大鼠体内表达及其产物延长胰岛移植物存活的作用，利用脂质体（Ｌｉｐｏｆｅｃｔｉｎ） 载体包裹ＣＴＬＡ４ＩｇｃＤＮＡ 质粒后转染鼠胰岛和肌肉细胞，检测移植后ＣＴＬＡ４Ｉｇ 基因表达水平和Ｔ 淋巴细胞转化率，观察ＣＴＬＡ４Ｉｇ 基因表达在延长糖尿病鼠胰岛移植物和大鼠存活时间的作用。结果： 胰岛移植术后实验（ Ａ） 组、对照（Ｂ） 组Ｔ 淋巴细胞转化率有明显差异（ Ｐ＜ ０ ．０５） 。Ａ 组胰岛移植后第７ 天２ 只大鼠血清ＣＴＬＡ４Ｉｇ 呈阳性（ 阳性率为２０ ％ ） ，分别为１４ ｎｇ／ ｍｌ 和３１ ｎｇ／ ｍｌ。Ｂ 组胰岛移植后维持血糖正常时间平均３ ．６ ±５ ．１ 天，Ａ 组胰岛移植后维持血糖正常时间平均１４ ．８ ±１２ ．３ 天，两组比较差异有显著性意义（ Ｐ＜ ０ ．０５ ） 。Ａ 组大鼠平均存活２４ ．０ ±１０ ．８ 天，最长４５ 天，Ｂ 组大鼠平均存活１０ ．８ ±４ ．８ 天，最长２１ 天，两组大鼠生存时间差异有统计学意义（ Ｐ＜ ０ ．０１） 。本实验结果提示：ＣＴＬＡ４Ｉｇ 基因可以在受体大鼠胰岛细胞或肌肉组织表达，其表达产物可使胰岛移植物和受体鼠存活时间明显延长。     

胰岛与Fas配体阳性睾丸细胞共同移植产生免疫豁免

目的通过胰岛与睾丸细胞共同移植诱导胰岛移植物长期生存。方法胶原酶、胰蛋白酶、Ｄｎａｓ酶消化制备睾丸ｓｅｒｔｏｌｉ细胞培养４８小时;纯化的供体（Ｗｉｓｔａｒ大鼠）胰岛５００个培养后的睾丸ｓｅｒｔｏｌｉ细胞共同移植,移植前后不用全身性免疫抑制剂,ＴＵＮＥＬ法标记胰岛移植物周围凋亡的淋巴细胞,ＳＡＢＣ法测定共同移植物ＦａｓＬ稳定表达情况。结果胰岛与１×１０７个睾丸ｓｅｒｔｏｌｉ细胞共同移植可以纠正链脲酶素所至的糖尿病高血糖状态达６０天（有效率达１００％,６／６）,单纯的胰岛移植或与１×１０５个睾丸ｓｅｒｔｏｌｉ细胞共同移植,移植物仅能存活５～６天。移植物周围可见明显的凋亡的淋巴细胞存在。结论胰岛与Ｆａｓ配体阳性睾丸细胞共同移植可以诱导局部免疫豁免,使移植物长时间存活。     

胸腺内注射可溶性异基因主要组织相容性复合物抗原诱导皮肤移植特异性耐受

用３ｍｏｌ／ＬＫＣｌ从Ｃ５７ＢＬ／６小鼠脾细胞提取可溶性主要组织相容性复合物（ＭＨＣ）抗原，注射到ＢＡＬＢ／Ｃ受体鼠胸腺内，诱导了成年小鼠对该异基因小鼠皮肤移植物的耐受。除在胸腺注射当天及第３天给予抗Ｔ细胞单克隆抗体外，不使用免疫抑制剂。实验组移植皮肤平均存活时间（ＭＳＴ）为８３天，对照组ＭＳＴ为１１天。诱导耐受的小鼠对第３供体的移植皮肤仍正常排斥（ＭＳＴ为１２天）。单向混合淋巴细胞反应，耐受小鼠脾脏淋巴细胞对特异供体的脾细胞无反应，对第３供体的脾细胞反应正常，对丝裂原刺激的增殖反应正常。显示诱导的耐受是供体特异性的，无非特异性免疫抑制。     

CTLA41Ig基因在糖尿病大鼠胰岛移植中的作用

为探讨融合蛋白（ＣＴＬＡ４Ｉｇ）基因在糖尿病大鼠体内表达及其产物延长胰岛移植物存活的作用，利用脂质体（Ｌｉｐｏｆｅｃｔｉｎ０载体包裹ＣＴＬＡ４ＩｇｃＤＮＡ质粒后转染鼠胰岛和肌肉细胞，检测移植后ＣＴＬＡ４Ｉｇ基因表达水平和Ｔ淋巴细胞转化率，观察ＣＴＬＡ４Ｉｇ基因表达在延长糖尿病鼠胰岛移植物和大鼠存活时间的作用。结果：胰岛移植术后实验（Ａ）组、对照（Ｂ）组Ｔ淋巴细胞转化率有明显差异（Ｐ〈０．０５）。Ａ     

免疫毒素及可溶性抗原诱导胰岛移植耐受

目的　通过静脉注入抗ＣＤ４ 、ＣＤ８ 免疫毒素及供体可溶性抗原诱导胰岛移植物免疫耐受。方法　供、受体分别为Ｗｉｓｔａｒ 大鼠和ＳＤ大鼠， 移植前１４ 天、７ 天分别将免疫毒素各２００ μｇ， 供体可溶性抗原５００ μｇ 经静脉注入受体， 然后将供体５００ 个胰岛移植于受体（ 糖尿病大鼠）左侧肾包膜下。结果　用免疫毒素及供体可溶性抗原联合处理组胰岛移植物存活时间显著延长（ Ｐ＜ ０ ．０１） ， 而单独应用抗ＣＤ４ 、ＣＤ８ 免疫毒素或供体可溶性抗原组仅能获得胰岛移植物存活时间轻度延长。结论　抗ＣＤ４、ＣＤ８ 免疫毒素及供体可溶性抗原联合应用可以诱导供体特异性免疫耐受     

免疫毒素及可溶性抗原诱导胰岛素移植耐受

目的 通过静脉注入抗ＣＤ４、ＣＤ８免疫毒素及供体可溶性抗原诱导胰岛植物免疫耐受。方法 供、受体分别为Ｗｉｓｔａｒ大鼠和ＳＤ大鼠,移植前１４天,７天分别将免疫毒素各２００μｇ,供体可溶性抗原５００μｇ经静脉注入受体,然后将供体５００个胰岛移植于受体（糖尿病大鼠）左侧肾包膜下。结果 用免疫毒素及供体可溶性抗原联合处理组胰岛移植物存活时间显著延长（Ｐ〈０．０１）。而单独应用抗ＣＤ４、ＣＤ８免疫毒素或供体     

早期移植肾功能异常的相关因素及其预后

目的 探讨早期移植肾功能异常的相关因素及其对移植肾长期存活的影响。方法 根据术后６个月内有无发生急性排斥反应和６个月时的血肌酐水平（ＳＣｒ６月）,将２５１例肾移植患者分为４组：Ａ、Ｂ组未发生急性排斥反应,前者ＳＣｒ６月〈１３０μｍｏｌ／Ｌ,后者ＳＣｒ６月≥１３０μｍｏｌ／Ｌ;Ｃ、Ｄ组为４组：Ａ、Ｂ且未发生急性排斥反应,前者ＳＣｒ６月〈１３０μｍｏｌ／Ｌ,后者ＳＣｒ≥１３０μｍｏｌ／Ｌ。术后各组的免     

糖尿病小鼠胰岛移植部位的实验研究

目的探讨小鼠肝内、肾包膜下等不同部位胰岛移植物生存时间及免疫学功能的差异。方法采用滤网法分离纯化胰岛,供体胰岛植入受体肝内及肾包膜下。用酶联免疫吸附试验 (ELISA)测定INF-γ的含量。3H-胸腺嘧啶脱氧核苷(3H-TdR)掺入法测定单向混合淋巴细胞反应。结果肾包膜下移植组胰岛生存时间(12．18±1．25)d明显长于肝内移植组[(7．09±0．70)d,P< 0．01]。单项混合淋巴细胞反应显示,肝内移植组淋巴细胞较肾包膜下移植组增殖明显(P<0．01)。上清液测IFN-γ含量,肝内移植组明显升高,差别有统计学意义(P<0．05)。结论不同移植部位, 胰岛的生存时间及免疫功能差异存在统计学意义,肾包膜下是胰岛移植的理想部位。     

新生猪Sertoli细胞与大鼠胰岛细胞联合移植延长大鼠移植胰岛的存活时间

目的 探讨新生猪Sertoli细胞(NPSCs)与大鼠胰岛细胞联合移植对延长大鼠同种异体胰岛移植物存活时间的作用及其主要的机制.方法 将糖尿病Wistar大鼠随机分为3组.(1)单纯移植组(n=6):单纯移植1500个胰岛当量(IEQ)的SD大鼠胰岛细胞至糖尿病大鼠的左肾包膜下;(2)分侧移植组(n=4):将1500个IEQ的SD大鼠胰岛细胞移植到糖尿病大鼠的左肾包膜下,同时将1×10~7个NPSCs移植到糖尿病大鼠的右肾包膜下;(3)混合移植组(n=6):将1500个IEQ的SD大鼠胰岛细胞和1×10~7个NPSCs混合移植到糖尿病大鼠的左肾包膜下.移植后每天监测各组的血糖水平,以了解移植物的存活时间;移植后发生排斥反应时获取移植物标本,行HE和免疫组织化学染色,观察移植物中CD3~+T淋巴细胞浸润情况及细胞凋亡调控基因(Bcl-2)和血红素氧合酶1(HO-1)基因的表达水平.结果 单纯移植组、分侧移植组和混合移植组胰岛移植物存活时间分别为(5.7±1.0)d、(5.3±0.5)d和(16.3±1.4)d,混合移植组存活时间较其他两组显著延长(P<0.05).单纯移植组移植区可见大量淋巴细胞浸润,主要为CD3+T淋巴细胞;混合移植组移植区Bcl-2基因呈高表达;各组移植区HO-1基因均有表达,差异不明显.结论 NPSCs与大鼠胰岛细胞联合移植可以延长大鼠同种异体胰岛移植物的存活时间,其机制可能与NPSCs抑制移植物淋巴细胞浸润、促进Bcl-2基因高表达的局部免疫调节作用有关.     

抗CD3单抗和供鼠骨髓细胞输注对小鼠皮肤移植存活的影响

目的 研究抗ＣＤ３单抗和供鼠骨髓细胞输注对小鼠皮肤移植存活的影响。方法 从供鼠Ｃ５７ＢＬ／６中分离提取骨髓细胞液,移植术后注入受鼠ＢＡＬＢ／Ｃ中,观察对异基因皮肤移植存活的影响。结果 骨髓组移植皮肤平均存活时间（ＭＳＴ）为１５．６ｄ,抗ＣＤ３单抗组为１０．１ｄ,正常对照组为７．７ｄ。结论 在免疫抑制下,供鼠骨髓输注可促进移植物的存活。     

Immunological characteristics of purified pancreatic islet grafts

In a DBA/2 (H-2d) pancreatic islet-to-B6AF1 (H-2b/k.d) recipient combination, the graft survival of hand-picked islets was compared with that of "crude digested" islets that were prepared simply by collagenase digestion and Ficoll gradient separation and were contaminated with lymph nodes and vascular and ductal tissue. Islet allografts were transplanted into the renal subcapsular space of streptozotocin-induced diabetic recipients. No immunosuppression was used. All the crude digested islet allografts were acutely rejected between days 7 and 18 with a median survival time (MST) of 10.2 +/- 2.5 days. In contrast, 33% (3/9) of the purified islet allografts survived more than 100 days. Simultaneous transplantation of purified islets and contaminating tissue resulted in a shorter graft survival (MST of 15.6 +/- 3.7 days). When 5 X 10(7) donor strain spleen cells were injected i.v. at the time of transplantation, all purified islet grafts were acutely rejected within 9 days. In addition, the rejection time of the purified islet allografts was inversely correlated with the number of donor spleen cells injected. These results indicate that contaminating tissues such as lymph nodes, vascular tissue, and ductal fragments present in the crude digested islet allografts are a major stimulus for induction of an immune response resulting in acute rejection of islet allografts.     

FK506 as the sole immunosuppressive agent for prolongation of islet allograft survival in the rat.

The purpose of the present study was to determine immunosuppressive effects of a new immunosuppressive agent, FK506, on rat islet allografts and also whether FK is toxic to the islet grafts since the diabetogenic effects of FK is controversial. Hand-picked clean fresh islets (WKA/Qdj:RT1u) were transplanted either beneath the renal capsule or into the liver via the portal vein of the diabetic (STZ, 60 mg/kg) rats (Lewis:RT1(1)). FK506 was administered s.c. for 7 days after transplantation. The mean survival times (MST)* of the renal subcapsular grafts receiving 0 (control), 0.32 or 1.0 mg/kg FK were 7.2 +/- 1.1 (mean +/- SD, n = 5), 13.8 +/- 4.8 (n = 4), and 20.2 +/- 8.0 days (n = 5), respectively. The MST of the intrahepatic grafts receiving 0, 0.1, 0.32, or 1.0 mg/kg FK were 4.4 +/- 1.1 (n = 5), 7.2 +/- 0.8 (n = 5), greater than 45.3 +/- 23.1 (n = 6) or greater than 54.4 +/- 8.8 days (n = 5), respectively. Histologically, islets were found easily in the liver of normoglycemic recipients for more than 60 days after transplantation and appeared intact, with well-granulated beta cells. Foci of mononuclear cells were occasionally seen adjacent to the islet cells. The plasma glucose of the recipients with 1.0 mg/kg FK fluctuated between 150 and 350 mg/dl without rejection. In the recipients treated with 3.2 mg/kg FK the plasma glucose of all the recipients (n = 3) returned to pretransplant levels by 21 days after transplantation. However, islet cells were present in the liver of all these recipients without mononuclear cell infiltration. Immunohistochemically islet grafts stained weakly for insulin, but to the same extent as the controls for glucagon and somatostatin. These findings clearly demonstrate the immunosuppressive effect of FK506 on islet allografts and the importance of the transplant site for prolongation of graft survival by FK, and also suggest that FK has toxic effects on the islet grafts (B cells) when used in high dosages.     

Indefinite survival of rat islet allografts following infusion of donor bone marrow without cytoablation

We have tested the effect of donor bone marrow cell (DBMC) infusion on the survival of pancreatic islet allografts in the rat, without the use of cytoablative recipient conditioning. Lewis and diabetic Brown Norway rats were used as donors and recipients, respectively. Donor islets were placed beneath the left renal capsule. Infusion of DBMC and temporary immunosuppression followed by delayed islet transplantation resulted in indefinite survival of all islet grafts (MST >180 days). Control animals demonstrated recurrent hyperglycemia (islet allografts rejection). Donor bone marrow derived cells were detected in the spleen and cervical lymph nodes of BN recipients of LEW bone marrow but not in the recipients of islet transplants alone. Second set full thickness skin grafts were performed in normal BN and in recipients of a previously successful ITX. Donor specific skin grafts were accepted in the animals that had received DBMC 40 days before the islet allograft, while animals receiving DBMC at the time of the islet allograft rejected the donor specific skin graft similarly to the controls. However, these animals did not reject a second set donor-specific islet transplant. The results indicate that radiation conditioning of the recipients was not necessary to induce microchimerism and graft acceptance in this rodent model of islet allotransplantation.     

Effect of transplantation site and alpha L3T4 treatment on survival of rat, hamster, and rabbit islet xenografts in mice

Rat, hamster, and rabbit islets were transplanted into diabetic C57BL/B6 mice. The effect on islet xenograft survival of low-temperature culture of the donor islets, alpha L3T4 treatment of the recipients for seven days, and transplantation of the grafts either in the renal capsule or in the liver via the portal vein was determined. Renal capsule transplants of control rat, hamster, and rabbit islets cultured at 37 degrees C for one day produced normoglycemia in the recipients, with the mean survival time (MST) of the grafts ranging from 14 to 19 days. Low temperature culture alone did not produce a significant increase in the survival time. Treatment of the recipients with alpha L3T4 produced a marked prolongation of xenograft survival for all three species receiving renal subcapsular transplants of control or low temperature cultured islets. The range of MST* was from 34 to 46 days. The intrahepatic site produced an even further prolongation of the survival of concordant rat islet xenografts treated in this manner, with 60% of the recipients still normoglycemic at 100 days after transplantation. This enhancing effect of the intrahepatic site on survival did not occur with the discordant xenografts of hamster and rabbit islets.     

The use of direct ultraviolet irradiation and cyclosporine in facilitating indefinite pancreatic islet allograft acceptance

We have previously shown that direct ultraviolet (UV) irradiation of islets can reduce their immunogenicity without alteration of their endocrine function and effect prolonged survival of islet allografts in the Lewis-to-ACI strain combination without the use of immunosuppression. This study extends that work to investigate the survival of UV-irradiated Wistar-Furth islets in streptozotocin-diabetic Lewis rats, in which case the recipient is a relatively "high responder" to W/F alloantigens. Lewis recipients of 24-hr cultured W/F islets uniformly rejected islet allografts within one week of transplantation while the additional immunosuppression with cyclosporine (CsA) at 15 or 30 mg/kg on days 0, +1, and +2 was ineffective in prolonging islet allograft survival. Wistar-Furth islets, which were UV-irradiated at 850-900 J/m2 and cultured for 24 hr prior to transplantation, did not survive any longer than those in control animals receiving untreated islets (MST 5.5 +/- 1 day). When UV irradiation of islets was combined with recipient peritransplant treatment with CsA at 15 mg/kg on days 0, +1, and +2 islet allograft survival was markedly prolonged (MST of 18 +/- 4.1 days). Treatment of diabetic recipients of UV irradiated islets with an increased dose of CsA (30 mg/kg) during the same peri-transplant period (0, +1, +2 days) resulted in 100% islet allograft survival beyond 120 days. This data demonstrate the effectiveness and synergism between the use of the pretransplant UV irradiation of islet allograft and the peritransplant immunosuppression of the recipient with CsA in inducing prolonged islet allograft survival in "high responder" recipients, in which the singular use of either modality may be ineffective.     

Evaluation of intrathymic islet transplantation in the prediabetic period.

BACKGROUND. Beta-cell destruction in type I diabetes mellitus results from a chronic autoimmune process. Exposure of thymic T cells to islet antigens during the prehyperglycemic phase of diabetes may alter the likelihood of autoimmune damage to beta cells in the native pancreas. Thus we evaluated whether prophylactic major histocompatibility complex (MHC)-incompatible intrathymic islet allografts could prevent hyperglycemia and native pancreatic beta-cell destruction. METHODS. At 4 to 6 weeks of age, diabetes-prone BioBreeding rats received intrathymic injection of 1500 to 2000 noncultured MHC-incompatible Lewis islets. No immunosuppression was administered. Age-matched littermates underwent intrathymic injection of saline solution. RESULTS. None of 13 BioBreeding rat recipients of prophylactic intrathymic Lewis islet allografts became hyperglycemic versus 13 of 13 control rats (p less than 0.001). The age at onset of diabetes in the control group ranged from 77 to 104 days (mean, 86 days). Normoglycemia in recipients of intrathymic islet allografts persisted for greater than 8 months after transplantation, and thymectomy (graft removal) did not precipitate hyperglycemia. CONCLUSIONS. Prophylactic intrathymic MHC-incompatible islet allografts effectively prevent hyperglycemia and native beta-cell destruction in an animal model of autoimmune diabetes. Rejection and autoimmune destruction of intrathymic MHC-incompatible islet allografts were not seen after transplantation in the prediabetic (prehyperglycemic) period. Intrathymic islet allografts at an early age (before puberty) preserve native beta-cell function and may prevent or retard thymic atrophy.     

Donor-specific antigen and cyclosporine in rat islet allografts

Combination therapy with one dose of 3 M KCl extracted donor-soluble antigen (Ag) and a short course of cyclosporine (CsA) has proven to prolong the survival of kidney allografts by enhancing specific T-suppressor populations. This regimen is tested in rat islet allografts in this study (Lewis to ACI). A 3-day perioperative course of 10 mg/kg/day CsA on Days -1, 0, and 1 did not prolong graft survival (MST = 10.7 +/- 2.5 days vs 9.4 +/- 1.2 days in controls). When this course of CsA therapy was combined with a single dose of donor antigen on Day -1, the survival time was prolonged slightly but significantly (MST = 14.0 +/- 5.8 days). Three cycles of a 3-day course of CsA therapy at 7-day intervals, a total of nine doses of 10 mg/kg/day CsA, were effective in delaying rejection of islet allografts (MST = 26.4 +/- 30.3). Moreover, combined therapy with donor antigen and three cycles of a 3-day course of CsA prolonged the survival of islet allografts (MST = 57.7 +/- 51.4 days) with 50% of recipients still normoglycemic at 60 days after transplantation. These findings indicate that the combination therapy of donor antigen with a short course of CsA has a powerful effect to prevent the rejection of islet allografts, as shown in kidney allografts, in rats.     

Intrathymic injection of donor alloantigens induces donor-specific vascularized allograft tolerance without immunosuppression.

The induction of donor-specific tolerance could prevent the side effects of immunosuppression while improving allograft survival. Male adult Buffalo (RT1b) rats underwent an intrathymic (IT), portal venous (PV), intrasplenic (IS), or subcutaneous (SQ) injection of 25 x 10(6) major histocompatibility complex (MHC) mismatched Lewis (RT1(1)), UV-B-irradiated Lewis (RT1(1)), ACI (RT1a), or syngeneic Buffalo (RT1b) splenocytes. At the completion of the donor alloantigen injection, 1 mL rabbit anti-rat lymphocyte serum (ALS) was administered intraperitoneally to the Buffalo recipients, and 21 days later a heterotopic Lewis or ACI heart was transplanted. Intrathymic injection of donor alloantigen induced a donor-specific tolerance that allowed the cardiac allograft to survive indefinitely (mean survival time [MST] > 140.7 days) in 84% of the recipients without further immunosuppression, whereas groups receiving antigen injections at other sites (PV, IS, and SQ) plus ALS rejected cardiac allografts in normal fashion (MST approximately 8.0 days). Buffalo recipient rats with long-term surviving Lewis cardiac allografts after Lewis IT injection and ALS subsequently rejected a heterotopic third-party ACI cardiac allograft in normal fashion (MST approximately 7 days), whereas a second Lewis cardiac allograft was not rejected (MST > 116 days). Microchimerism is unlikely because Lewis allograft survival was also prolonged (MST > 38.7 days) in rats receiving UV-B-irradiated splenocytes IT, which cannot proliferate. Survival of Lewis renal allografts was also prolonged, but not indefinitely, in Buffalo recipients possessing a long-term surviving Lewis cardiac allograft (MST approximately 17.6 days versus 7 days for control). This model emphasizes the potential role of exposure of immature thymocytes to foreign donor alloantigens during maturation in the thymic environment for the development of unresponsiveness to an MHC-mismatched donor-specific vascularized allograft.     

Does intrathymic injection of alloantigen-presenting cells before islet allo-transplantation prolong graft survival?

Abstract Current immunosuppressive agents have potentially dangerous side-effects, are nonspecific and most are also diabetogenic. We investigated tolerance induction with intrathymic injection of purified antigen-presenting cells (APC) plus a single dose of anti-lymphocyte serum (ALS) intraperitoneally before allogeneic islet transplantation in the rat model WAG to Lewis (RT1^u to RT1¹. Purified donor APC [non-parenchymal cells (NPC) or dendritic cells (DC)] were prepared from liver and spleen, respectively. Isograft function for more than 120 days proved that islet isolation, purification and transplantation procedures were adequate. A total of WAG DC (4 times 10⁵) or NPC (2 times 10⁶) in 20 μl were injected into both lobes of the thymus of 140–210 g Lewis recipients followed by a single injection of ALS. Three days later, diabetes was induced with streptozotocin (60 mg/kg). Four days later allogeneic islets were grafted into the liver by intraportal injection of 3000 WAG islets. Control animals ( n = 8) received 20 μ saline intrathymically instead of APC. Graft function was assessed by blood glucose measurements with glucose levels above 15 mmol/l on 3 consecutive days defined as graft rejection. Animals given DC ( n = 9) or NPC ( n = 8) intrathymically plus 1 ml of ALS, rejected their grafts in an accelerated fashion with a median survival time (MST) of 3 days. However, control animals rejected their grafts with a MST of 7 days, but with two animals surviving for more than 2 months. In conclusion, intrathymic inoculation with purified APC plus a single dose of ALS did not prolong allogeneic islet graft function but induce? accelerated rejection of the islet allografts.     

The effect of cyclosporin-A, low-temperature culture, and anti-Ia antibodies on prevention of rejection of rat islet allografts

The effect of cyclosporin-A, low-temperature culture, and anti-Ia antibodies on prevention of rejection of rat islet allografts was determined. Wistar-Furth islets were isolated by the collagenase technique and transplanted via the portal vein into diabetic Lewis recipients. Cyclosporin-A (30 mg/kg) injected at 0, 1, and 2 days after transplantation produced a significant prolongation of survival of the islet allografts (MST greater than 35.7 +/- 7.0 days) when hand-picked donor islets were used, whereas only a modest prolongation of survival (14.0 +/- 1.6 days) was obtained using donor islets removed directly from Ficoll gradients. This difference in survival was apparently due to the large number of lymphoid, antigen-presenting cells that were present in the islet fraction removed directly from the Ficoll gradients. Treatment of donor, hand-picked islets with a mixture of cross-reactive anti-Ia antibodies and complement without cyclosporin-A therapy did not prolong the survival of islet allografts (MST, 6.5 +/- 0.4 days versus 7.0 +/- 0.5 days in controls). In contrast, treatment of the donor islets with the mixture of anti-Ia antibodies and complement in conjunction with the 3-day course of cyclosporin-A therapy produced an 83% survival of the islet allografts at 60 days after transplantation. In vitro culture of hand-picked donor islets at 24 degrees C for 7 days and the 3-day course of cyclosporin-A therapy produced a 100% survival of the allografts at 60 days after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)