Karussis D, Vourka-Karussis U, Mizrachi-Koll R, Abramsky O
Department of Neurology, Hadassah Hebrew University Hospital, Jerusalem, Israel.
Mult Scler. 1999 Feb;5(1):17-21. doi: 10.1177/135245859900500104.
Experimental autoimmune encephalomyelitis (EAE) is an inducible autoimmune disease widely used as a model of the acute/relapsing stage of multiple sclerosis. We have previously shown that treatment of EAE-mice with high doses of cyclophosphamide (CY) (350 mg kg), followed by syngeneic bone marrow transplantation (SBMT), completely abrogates the clinical paralytic signs and even prevents the appearance of new relapses in the chronic-relapsing model of the disease. In the present study we examined whether this treatment protocol induces long term tolerance and whether this tolerance is antigen-specific. EAE was induced by immunization with spinal cord homogenate (MSCH) in complete Freund's adjuvant (CFA). The treatment with CY and SBMT was performed on day 6 post immunization. Treated and untreated mice were rechallenged with MSCH, or a non-relevant antigen (OVA) in CFA at various stages after the first paralytic attack. In contrast to previous data showing that animals recovering from acute EAE are usually refractory to re-induction of the disease, repeated injections of MSCH at different sites from the initial immunization, followed by i.v. injection of inactivated Bordetella bacteria, 2, 4 and 6 months after the initial EAE-induction, caused a severe and usually lethal relapse in all the untreated, control animals. Mice treated with CY and SBMT were resistant to all rechallenges with the same encephalitogenic inoculum. Following the second rechallenge, peripheral lymph node cells were examined in vitro for their proliferative responses to myelin antigens or to OVA. Lymphocytes obtained from CY+SBMT treated mice did not proliferate in vitro in response to myelin basic protein (MBP), but proliferated against OVA, when immunized with this antigen, after SBMT. Adoptive transfer of lymphocytes from tolerant mice to naive recipients did not transfer resistance to EAE-induction. Our results indicate that high doses of CY, followed by SBMT, induce long term antigen-specific tolerance presumably by a mechanism of clonal deletion or anergy.
实验性自身免疫性脑脊髓炎（EAE）是一种可诱导的自身免疫性疾病，被广泛用作多发性硬化症急性/复发阶段的模型。我们之前已经表明，用高剂量环磷酰胺（CY）（350 mg/kg）治疗EAE小鼠，随后进行同基因骨髓移植（SBMT），可完全消除临床麻痹症状，甚至可预防该疾病慢性复发模型中出现新的复发。在本研究中，我们研究了这种治疗方案是否能诱导长期耐受性，以及这种耐受性是否具有抗原特异性。通过在完全弗氏佐剂（CFA）中用脊髓匀浆（MSCH）免疫诱导EAE。在免疫后第6天进行CY和SBMT治疗。在首次麻痹发作后的不同阶段，用MSCH或CFA中的无关抗原（OVA）对治疗组和未治疗组小鼠进行再次攻击。与之前的数据显示从急性EAE恢复的动物通常对疾病的再次诱导具有抗性相反，在初次EAE诱导后2、4和6个月，在与初次免疫不同的部位重复注射MSCH，随后静脉注射灭活的博德特氏菌，导致所有未治疗的对照动物出现严重且通常致命的复发。用CY和SBMT治疗的小鼠对相同的致脑炎接种物的所有再次攻击均具有抗性。在第二次再次攻击后，体外检测外周淋巴结细胞对髓鞘抗原或OVA的增殖反应。从接受CY+SBMT治疗的小鼠获得的淋巴细胞在体外对髓鞘碱性蛋白（MBP）无增殖反应，但在用该抗原免疫后，在SBMT后对OVA有增殖反应。将耐受小鼠淋巴细胞过继转移至未致敏受体并未转移对EAE诱导的抗性。我们的结果表明，高剂量CY随后进行SBMT，可能通过克隆清除或无反应性机制诱导长期抗原特异性耐受性。
