Mixed allogeneic chimerism as a reliable model for composite tissue allograft tolerance induction across major and minor histocompatibility barriers.
Mixed allogeneic chimerism as a reliable model for composite tissue allograft tolerance induction across major and minor histocompatibility barriers.
复制标题
DOI：
10.1097/00007890-200109150-00009
复制
发表时间：
2001-09-15
期刊：
影响因子：
6.2
通讯作者：
Mathes, SJ
中科院分区：
文献类型：
--
作者：
Foster, RD;Ascher, NL;Mathes, SJ
背景虽然使用免疫抑制药物可以延长动物的复合组织同种异体移植物（CTA）存活时间，但临床环境中CTA的长期免疫抑制可能对大多数患者来说是不可接受的。本研究的目的是开发一种模型，用于在成年大鼠中跨主要MHC错配的可靠CTA耐受诱导，而不需要长期的免疫抑制。通过使用具有强MHC不相容性的大鼠品系[WF（RT 1A（u）），ACI（RT 1A（a））] WF + ACI --> WF，n=23制备混合的同种异体嵌合体。用低剂量辐射（500-700 cGy）预处理受体动物的骨髓（BM），然后用T细胞耗尽的同基因（WF）和同种异体（ACI）细胞的混合物重建。此外，受体动物在骨髓移植（BMT）前5天接受单次剂量的抗淋巴细胞血清（10 mg），并在BMT前一天至BMT后10天接受他克莫司（1 mg/kg/天）。在骨髓移植后12个月进行后肢移植。五只动物在移植前接受了辐照（1000 cGy）的肢体同种异体移植物。在骨髓重建和后肢移植后3个月和12个月，通过流式细胞术对大鼠嵌合体进行表征（血流中存在的供体细胞百分比）。在18/23只动物中，外周血淋巴细胞嵌合体（WF/ACI）在BM重建后> 12个月保持稳定。存在淋巴和骨髓谱系的多谱系嵌合体，表明多能大鼠干细胞的植入已经发生。在供体嵌合性> 60%的动物中（n=18），在研究期间不存在肢体排斥的迹象。所有嵌合体< 20%的动物（n=5）在临床和组织学上均出现中度排斥体征。21只大鼠中有14只在> 60天时出现了粗大运动和感觉神经再支配（负重、脚趾伸展）。术后流式细胞术研究表明，所有研究动物（n=10）中均存在稳定的嵌合体。5/5只接受辐照肢体移植的动物在> 100天时未显示GVHD迹象。稳定的混合异基因嵌合体。可在大鼠后肢复合组织同种异体移植模型中实现。混合异基因嵌合体的后肢同种异体移植物显示出延长的无排斥存活。预计会有部分功能恢复。作为后肢同种异体移植物的一部分移植的BM在GVHD的病因学中起作用。移植前对骨髓的处理可能影响GVHD的发生。这是第一个可靠的大鼠后肢模型，证明了成年动物在主要MHC错配中的无排斥CTA存活，而无需长期使用免疫抑制剂。
Background. Although prolonged composite tissue allograft (CTA) survival is achievable in animals using immunosuppressive drugs, long-term immunosuppression of CTAs in the clinical setting may be unacceptable for most patients. The purpose of this study was to develop a model for reliable CTA tolerance induction in the adult rat across a major MHC mismatch without the need for long-term immunosuppression.Methods. Mixed allogeneic chimeras were prepared by using rat strains with strong MHC incompatibility [WF (RT1A(u)), ACI (RT1A(a))] WF + ACI --> WF, n=23. The bone marrow (BM) of recipient animals was pretreated with low-dose irradiation (500-700 cGy), followed by reconstitution with a mixture of T cell-depleted syngeneic (WF) and allogeneic (ACI) cells. Additionally, the recipient animals received a single dose of anti-lymphocyte serum (10 mg) 5 days before bone marrow transplantation (BMT) and tacrolimus (1 mg/kg/day) from the day before BMT to 10 days post-BMT. Hindlimb transplants were performed 12 months after BMT. Five animals received a limb allograft irradiated (1000 cGy) just before transplantation. Rat chimeras were characterized (percentage of donor cells present within the bloodstream) by flow cytometry at 3 and 12 months after BM reconstitution and after hindlimb transplantation.Results. Peripheral blood lymphocyte chimerism (WF/ACI) remained stable > 12 months after BM reconstitution in 18/23 animals. Multi-lineage chimerism of both lymphoid and myeloid lineages was present, suggesting that engraftment of the pluripotent rat stem cell had occurred. In animals with donor chimerism > 60% (n=18) no sign of limb rejection was present for the duration of the study. All animals with chimerism < 20% (n=5) developed moderate signs of rejection clinically and histologically. Gross motor and sensory reinnervation (weight bearing, toe spread) developed at > 60 days in 14/21 rats. Postoperative flow cytometry studies demonstrated stable chimerism in all animals studied (n=10). Five out of five animals with irradiated limb transplants showed no sign of GVHD at > 100 days.Conclusions. Stable mixed allogeneic chimerism. can be achieved in a rat hindlimb model of composite tissue allotransplantation. Hindlimb allografts to mixed allogeneic chimeras exhibit prolonged, rejection-free survival. Partial functional return should be expected. The BM transplanted as part of the hindlimb allograft plays a role in the etiology of GVHD. Manipulating that BM before transplantation may influence the incidence of GVHD. This represents the first reliable rat hindlimb model demonstrating rejection-free CTA survival in an adult animal across a major MHC mismatch without the long-term need for immunosuppressive agents.