Zhu Z X, Fan L Y, Wang Q
Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, PR China.
Eur Surg Res. 2011;46(3):109-17. doi: 10.1159/000323011. Epub 2011 Jan 15.
The conditioning regimen to induce chimerism for immune tolerance is usually accompanied by high toxicity and graft-versus-host disease (GVHD). Our aim was to explore a nontoxic strategy for the induction of mixed chimerism by pretreatment with anti-CD25 monoclonal antibody (mAb), cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin (CTLA4Ig) and anti-CD154 mAb.
A total of 30 Lewis recipient rats (RT1l) were randomly divided into control (A and B) and treated (C, D and E) groups. Recipients serving as controls were without any pretreatment (group A) or pretreated with anti-CD25 mAb, CTLA4Ig and anti-CD154 mAb on days 0, 2, 4, 6 and 8 without bone marrow transplantation (BMT; group B). In the treated groups, the recipients were pretreated with anti-CD25 mAb and CTLA4Ig (group C), with anti-CD25 mAb and anti-CD154 mAb (group D) or with anti-CD25 mAb, CTLA4Ig and anti-CD154 mAb (group E) on days 0, 2, 4, 6 and 8 plus BMT [2 × 10(8) unmodified whole bone marrow cells from Brown Norway donor rats (RT1n)] on day 0. Full-thickness skin grafts from donor-specific Brown Norway rats were grafted to the dorsal thoracic wall of Lewis recipients on day 8. GVHD was assessed after BMT, and chimerism and T cell apoptosis on days 7, 21, 35 and 49 were detected by flow cytometry.
GVHD was not observed in any groups. On days 7, 21 and 35, hematopoietic chimerism was present and maintained in the recipients of the 3 treated groups (groups C, D and E), and thereafter disappeared on day 49. The rate of chimerism in group E was significantly higher compared to that in group C on day 7 and that in group C or D on day 21, but there was no significant difference on day 35 among the 3 groups. The rate of T cell apoptosis in group C, D or E was significantly higher than in group A or B on days 14, 21 and 35. The grafted skin survival in group C, D or E was longer than in group A or B, and survival was significantly longer in group E than in group C or D.
Preconditioning with anti-CD25 mAb, CTLA4Ig and anti-CD154 mAb could effectively induce chimerism and immune tolerance without GVHD in a major histocompatibility complex-disparate rat model. This strategy may be attractive for induction of transplantation tolerance. T cell apoptosis is one of the important considerations in tolerance induction.
诱导嵌合体以实现免疫耐受的预处理方案通常伴随着高毒性和移植物抗宿主病（GVHD）。我们的目的是探索一种通过抗CD25单克隆抗体（mAb）、细胞毒性T淋巴细胞相关抗原4免疫球蛋白（CTLA4Ig）和抗CD154 mAb预处理来诱导混合嵌合体的无毒策略。
将30只Lewis受体大鼠（RT1l）随机分为对照组（A和B）和治疗组（C、D和E）。作为对照的受体不进行任何预处理（A组），或在第0、2、4、6和8天用抗CD25 mAb、CTLA4Ig和抗CD154 mAb进行预处理但不进行骨髓移植（BMT；B组）。在治疗组中，受体在第0、2、4、6和8天用抗CD25 mAb和CTLA4Ig（C组）、抗CD25 mAb和抗CD154 mAb（D组）或抗CD25 mAb、CTLA4Ig和抗CD154 mAb（E组）进行预处理，并在第0天接受BMT [来自Brown Norway供体大鼠（RT1n）的2×10(8)个未修饰的全骨髓细胞]。在第8天，将供体特异性Brown Norway大鼠的全层皮肤移植到Lewis受体的胸壁背部。在BMT后评估GVHD，并通过流式细胞术检测第7、21、35和49天的嵌合体和T细胞凋亡情况。
所有组均未观察到GVHD。在第7、21和35天，3个治疗组（C、D和E组）的受体中存在并维持造血嵌合体，此后在第49天消失。与C组在第7天以及C组或D组在第21天相比，E组的嵌合体率显著更高，但在第35天3组之间无显著差异。在第14、21和35天，C、D或E组的T细胞凋亡率显著高于A组或B组。C、D或E组移植皮肤的存活时间长于A组或B组，且E组的存活时间显著长于C组或D组。
在主要组织相容性复合体不相合的大鼠模型中，用抗CD25 mAb、CTLA4Ig和抗CD154 mAb进行预处理可有效诱导嵌合体和免疫耐受，且无GVHD。该策略可能对诱导移植耐受具有吸引力。T细胞凋亡是诱导耐受时的重要考虑因素之一。
