小鼠同基因型移植物抗宿主病模型建立及其免疫机制初步探讨

Establishment and immunological mechanism of mice syngeneic graft versus host disease model

目的：建立小鼠同基因型移植物抗宿主病模型，初步探讨小鼠同基因型移植物抗宿主病的免疫发生机制。方法：小鼠接受致死剂量的X线照射后，通过尾静脉注射同基因骨髓细胞进行骨髓移植和免疫重建，并于当天腹腔注射CsA进行诱导，连续21d。对照组小鼠腹腔注射相同体积和相同时间的橄榄油。停用CsA和橄榄油后观察小鼠是否出现同基因型移植物抗宿主病（SGVHD），若连续3次体重下降即可认为SGVHD阳性。取各组小鼠的肝脏、结肠、耳朵、皮肤和胸腺进行组织学检查；同时取小鼠的肝脏和结肠进行CD137mRNA和细胞因子IL-12、IFN-γ和TNF-αmRNA的检测。结果：CsA可诱导同基因型骨髓移植小鼠产生GVHD样症状，诱导组小鼠有67％出现SGVHD，而移植对照组未出现SGVHD。SGVHD阳性小鼠结肠和肝脏中CD137mRNA水平和IL-12、IFN-γ和TNF-αmRNA水平较移植对照组小鼠和诱导组中未出现SGVHD小鼠的水平升高，组织病理检查发现结肠和肝脏有大量炎细胞浸润。SGVHD阳性小鼠的胸腺大小与SGVHD呈负相关。结论：CsA可诱导X射线照射的同基因型骨髓移植小鼠产生SGVHD症状，CD137、细胞因子IL-12、IFN-7和TNF-α以及胸腺再生状态参与了SGVHD的病理机制。

Objective：To set up mouse syngeneic graft versus host disease （SGVHD） model and explore primarily the immunological mechanism of SGVHD. Method： Following lethally irradiated with X-ray, C3H/HeJ mice were reconstructed with bone marrow cells i. v. via tail vein on 0 day. Starting on the day of transplantation, SGVHD were induced with CsA （15 mg/kg） for 21 days. After cessation of CsA, the clinical symptoms of SGVHD were observed. The histological changes of mice liver, colon, skin, thymus and ear were examined by routine pathological methods, meanwhile, the mRNA of CD137, IL-12, IFN-γ and TNF-α of mice colon and liver were examined with RT-PCR. Result：CsA can induce GVFID-like symptoms in syngeneic bone marrow transplantation recipients mice and the incidences of SGVHD were 67% in CsA-induced group and 0% in control group, respectively. The enhanced levels of CD137, IL-12, IFN-γ and TNF-α mRNA and inflammatory cells infiltrates were found in liver and colon of SGVHD mice. Conclusion：CsA can induce syngeneic BMT recipients mice to develop SGVHD and the mechanism of SGVHD is involved with enhanced levels of CD137, IL-12, IFN-γ and TNF-α, inflammatory cells infiltrating and thymus regeneration.