Department of Hematology, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
Restor Neurol Neurosci. 2011;29(3):177-85. doi: 10.3233/RNN-2011-0590.
Hematopoietic stem cell transplantation (HSCT) has been proposed as a novel therapy for multiple sclerosis (MS). CD4 + CD25 + regulatory T cells (Tregs) expressing Foxp3 play an important role in the maintenance of immune tolerance to self. Our study was conducted to confirm the efficiency of nonmyeloablative conditioning and syngeneic bone marrow transplantation (BMT) on experimental autoimmune encephalomyelitis (EAE) mice and to determine whether Tregs plays a role in the underlying mechanism.
EAE were induced in C57BL/6 mice and were randomly divided into 4 groups: the Conditioning group received the conditioning regimen, the Normal-EAE BMT group received conditioning and bone marrow (BM) grafts from normal mice, the EAE-EAE BMT group received conditioning and BM grafts from EAE mice and the EAE control group received no further therapy. The cumulative clinical score was used to assess the efficacy of the different treatments, and the proportion of Tregs in the spleen was measured by flow cytometry on day 40, 80 and 120 after BMT. Foxp3 mRNA expression was assessed by real-time PCR, and the expression of Foxp3 protein was tested by western blot on day 120 after BMT.
Conditioning and conditioning with BMT led to a significant clinical improvement on day 80 after BMT compared with EAE without further treatment. On day 120 after BMT, the clinical score of the Conditioning group showed no significant difference from that of the EAE control group, whereas BMT led to a further amelioration of the disease score. On day 80 and day 120 after BMT, the proportions of Tregs of the two BMT groups were significantly higher than that in EAE control group, whereas no statistically significant difference was found between the Conditioning group and the EAE control group. On day 120 after BMT, the Foxp3 mRNA level and Foxp3 protein expression was higher in the two BMT groups than in EAE control group or Conditioning group.
Nonmyeloablative conditioning could temporarily reverse already established EAE, but it was not sufficient for the induction of long-term EAE remission. Transplantation by BM cells from healthy or diseased donors was necessary and responsible for complete and long-time remission of EAE, and these beneficial effects may be the result of the induction of Tregs and the Treg-related factor Foxp3.
造血干细胞移植（HSCT）已被提议作为多发性硬化症（MS）的一种新疗法。表达 Foxp3 的 CD4 + CD25 + 调节性 T 细胞（Tregs）在维持对自身的免疫耐受中发挥重要作用。我们的研究旨在证实非清髓性预处理和同基因骨髓移植（BMT）对实验性自身免疫性脑脊髓炎（EAE）小鼠的疗效，并确定 Tregs 是否在潜在机制中发挥作用。
在 C57BL/6 小鼠中诱导 EAE，并将其随机分为 4 组：预处理组接受预处理方案，正常-EAE BMT 组接受来自正常小鼠的预处理和骨髓（BM）移植物，EAE-EAE BMT 组接受来自 EAE 小鼠的预处理和 BM 移植物，EAE 对照组未接受进一步治疗。累积临床评分用于评估不同治疗方法的疗效，流式细胞术在 BMT 后第 40、80 和 120 天测量脾内 Tregs 的比例。实时 PCR 评估 Foxp3 mRNA 表达，BMT 后第 120 天通过 Western blot 测试 Foxp3 蛋白表达。
与未经进一步治疗的 EAE 相比，预处理和预处理加 BMT 导致 BMT 后第 80 天临床症状明显改善。BMT 后第 120 天，预处理组的临床评分与 EAE 对照组无显著差异，而 BMT 导致疾病评分进一步改善。BMT 后第 80 和 120 天，两个 BMT 组的 Tregs 比例明显高于 EAE 对照组，而预处理组与 EAE 对照组之间无统计学差异。BMT 后第 120 天，两个 BMT 组的 Foxp3 mRNA 水平和 Foxp3 蛋白表达均高于 EAE 对照组或预处理组。
非清髓性预处理可暂时逆转已建立的 EAE，但不足以诱导长期 EAE 缓解。来自健康或患病供体的 BM 细胞移植是必要的，并负责 EAE 的完全和长期缓解，这些有益作用可能是 Tregs 和与 Treg 相关的 Foxp3 诱导的结果。
