MHC基因胸腺转移诱导异基因小鼠皮肤移植免疫耐受

Expression of allogenic MHC gene in thymus by retroviralmediated gene transfer induces tolerance

目的通过胸腺内注射质粒ＰＸＮ（Ｎ２Ｂ１９Ｈ２Ｋｂ），表达外源性主要组织相容性抗原复合物（ＭＨＣ）抗原，以小鼠皮肤移植为模型，诱导移植免疫耐受，为免疫耐受提供理论和实验依据。方法应用逆转录病毒载体介导的基因转移技术，通过ＢＡＬＡ／Ｃ胸腺内注射质粒ＰＸＮ（Ｎ２Ｂ１９Ｈ２Ｋｂ），将外源性ＭＨＣ基因转移到胸腺细胞，１４天后行异基因小鼠皮肤移植。应用聚合酶链反应（ＰＣＲ），反转录聚合酶链反应（ＲＴＰＣＲ），单克隆抗体免疫荧光染色流式细胞仪检测胸腺细胞ＤＮＡ，ｍＲＮＡ和ＭＨＣ蛋白质表达。结果外源性ＭＨＣ基因已整合到靶细胞染色体ＤＮＡ并有效地转录，胸腺细胞表面有外源性ＭＨＣ分子表达，转染效率为５％，胸腺内注射质粒ＰＸＮ（Ｎ２Ｂ１９Ｈ２Ｋｂ）能明显延长异基因小鼠的皮肤移植时间，平均２７天，对照为１０天（Ｐ＜０００１）。受体鼠脾细胞对ＣｏｎＡ的增殖反应在正常范围。结论供体鼠ＭＨＣ基因转移至受体鼠胸腺诱导了对供体皮肤移植的免疫耐受。

Objective A mice skin graft tolerence model was constructed by intrathymic injection of retroviral vector PXN(N2B19H2Kb) to express exogenous major histocompatibality complex(MHC).It could add theoritical and experitmental data for tolerence . Methods Retroviral vector PXN(N2B19H2Kb) was injected into BALA/C thymus directly to express MHC of C57BL/6(H2 b);and the polymerase chain reaction (PCR) , the reverse transcription polymerase chain reaction (RTPCR) and flow cytometry assays were used to check DNA,mRNA and MHC protein expression in thymocytes. Results Allogenic MHC gene has been integrated into the chromosomal DNA of BALA/C thymus and expressed stably ;it induced allogenic mouse skin graft tolerance:27days vs 10 days(P<0001).The reaction of splenocytes in tolerance mice to ConA was in normal range. Conclusion Allogenic MHC gene transferring into recepient thymus directly could induce tolerance to allogenic mice.