Lakey J R, Singh B, Warnock G L, Rajotte R V
Department of Surgery, University of Alberta, Edmonton, Canada.
Transplantation. 1994 Apr 27;57(8):1213-7. doi: 10.1097/00007890-199404270-00013.
Islet transplantation can provide a therapeutic option for patients who suffer from type 1 diabetes mellitus, especially if current aggressive immunosuppression could be eliminated. In vitro immunomodulation has achieved this goal for islet allografts--however, strategies must be developed to prevent B cell lysis secondary to the chronic autoimmune process of diabetes. Previously, we have found that adjuvant therapy with CFA was effective in preventing the onset of diabetes and the recurrence of B cell lysis post-islet transplantation. In this study we evaluated the efficacy of BCG, a more clinically relevant immunoadjuvant, to prevent recurrent autoimmune damage to islets grafted into diabetic NOD mice. Highly purified islets were isolated from either 5-7-week-old prediabetic NOD mice or 5-8-week-old CBA/J mice using standard islet isolation techniques. Four hundred purified islets were transplanted into the kidney capsule of diabetic NOD recipients. A single dose of BCG was administered in recipients of syngeneic (gp 1) and allogeneic islets (gp 2). In gp 1, 8 of 10 BCG-treated syngeneic recipients remained normoglycemic for > 100 days posttransplant. In untreated recipients of syngeneic islets (gp 3) the graft failed at 19 days (n = 16) (P value, gp 1 vs. gp 3 < 0.001). In untreated allograft recipients, islet grafts functioned for 11 days (n = 8), which did not differ significantly (P = NS) from the BCG-treated allografts (gp 4) (14 days, n = 7). In 6 mice with long-term graft function, a second syngeneic graft implanted into the contralateral kidney maintained normoglycemia for 50 days following the removal of the first islet graft. Histological examination of the grafts from gp 1 mice showed granulated B cells with periinsular lymphocytes, while those of the control animals showed lytic B cells and marked lymphocytic infiltration. We conclude that adjuvant therapy with a single dose of BCG can prevent the recurrent autoimmune insulitis, but not allograft rejection in islets transplanted into NOD mice, and that a state of unresponsiveness is induced to allow acceptance of a second syngeneic graft. These data suggest that adjuvant therapy may be useful to sustain the function of transplanted islets in the type 1 diabetic.
胰岛移植可为1型糖尿病患者提供一种治疗选择，特别是在当前激进的免疫抑制措施能够消除的情况下。体外免疫调节已在胰岛同种异体移植中实现了这一目标——然而，必须制定策略来预防继发于糖尿病慢性自身免疫过程的B细胞裂解。此前，我们发现用弗氏完全佐剂（CFA）进行辅助治疗可有效预防糖尿病的发生以及胰岛移植后B细胞裂解的复发。在本研究中，我们评估了卡介苗（BCG）（一种更具临床相关性的免疫佐剂）预防移植到糖尿病NOD小鼠体内的胰岛发生复发性自身免疫损伤的疗效。使用标准胰岛分离技术从5 - 7周龄的糖尿病前期NOD小鼠或5 - 8周龄的CBA/J小鼠中分离出高度纯化的胰岛。将400个纯化的胰岛移植到糖尿病NOD受体的肾包膜中。对同基因（gp 1）和异基因胰岛受体（gp 2）给予单剂量的卡介苗。在gp 1组中，10只接受卡介苗治疗的同基因受体中有8只在移植后100多天保持血糖正常。在未治疗的同基因胰岛受体（gp 3）中，移植物在第19天失败（n = 16）（P值，gp 1组与gp 3组相比<0.001）。在未治疗的同种异体移植受体中，胰岛移植物发挥功能11天（n = 8），与接受卡介苗治疗的同种异体移植物（gp 4）（14天，n = 7）相比无显著差异（P =无统计学意义）。在6只具有长期移植物功能的小鼠中，在移除第一个胰岛移植物后，植入对侧肾脏的第二个同基因移植物维持血糖正常50天。对gp 1组小鼠的移植物进行组织学检查显示有带胰岛周围淋巴细胞的颗粒状B细胞，而对照动物的移植物显示有裂解的B细胞和明显的淋巴细胞浸润。我们得出结论，单剂量卡介苗辅助治疗可预防移植到NOD小鼠体内的胰岛发生复发性自身免疫性胰岛炎，但不能预防同种异体移植排斥，并且可诱导一种无反应状态以允许接受第二个同基因移植物。这些数据表明辅助治疗可能有助于维持1型糖尿病患者移植胰岛的功能。
