MECHANISM OF ALTERATION OF ALLOGRAFT ANTIGENICITY

我们的目标是开发高压氧培养条件，为 血管器官移植可提高移植物存活率。至 为了实现这一目标，我们建议进行研究，以确定分子和 高压氧诱导MHC的生化机制(S) I类下调和延长小鼠同种异体甲状腺移植物存活。 这项研究包括三个相互关联的部分，1)发展和 生物化学研究的体外模型系统的表征 HOC诱导的MHC下调及免疫学改变 性质；2)氧的作用和温度的测定 同种异体移植物存活增加与MHC下调的依赖关系 小鼠甲状腺模型系统；3)所获得信息的应用 第1及2部至同种异体胰岛移植物。第一部分和第二部分将 用Epstein-Barr转化的淋巴母细胞系完成 (LCL)和小鼠同种异体甲状腺移植系统。结构的修改 MHC I类分子将通过2D凝胶电泳法进行检测 计算机辅助分析和β2-微球蛋白交换率。 将进行原位杂交、Northern杂交和核径流分析 用于确定HOC诱导的基因组结构变化。一种能力 LCL作为细胞毒性T细胞的靶点和作为刺激因子 单向混合淋巴细胞培养将用于确定高压氧 氧培养可引起免疫特性的改变。角色 MHC下调中氧的含量将通过以下方法定量测定 LCL体外和体内的CELISA和流式细胞术 通过用氮或氦代替氧的同种异体移植系统。类似 MHC下调与同种异体移植物延长的温度依赖性 存活率将在体外和体内确定。最后， 高压氧培养的甲状腺刺激同种异体移植物的能力 体内排斥反应(CTL的产生)将使用有限稀释法进行检测 分析。 第1部分和第2部分中生成的信息将用于设计HOC 保持胰岛功能完整性的系统，但产生MHC I类 分子下调和延长同种移植物和异种移植物存活时间。

Our aim is to develop hyperbaric oxygen culture conditions that provide enhanced graft survival to the transplantation of vascularized organs. To accomplish this goal, we propose studies to identify the molecular and biochemical mechanism(s) of hyperbaric oxygen culture(HOC)-induced MHC class I down regulation and prolonged murine thyroid allograft survival. The study consists of three interrelated parts, 1) the development and characterization of an in vitro model system for biochemical studies of HOC-induced MHC down regulation and alteration in the immunological properties; 2) determination of the role of oxygen and the temperature dependence of MHC down regulation and increased allograft survival in a murine thyroid model system; and 3) application of the information gained in parts 1 and 2 to islet allografts and xenografts. Parts one and two will be accomplished using an Epstein-Barr transformed lymphoblastoid cell line (LCL) and the murine thyroid allograft system. Structural modification of the MHC class I molecule will be examined by 2D gel electroporesis with computer assisted analyses and the rate of beta 2-microglobulin exchange. In situ hybridization, northern blot and nuclear runoff analysis will be used to determine HOC-induced alterations in genomic structure. The ability of the LCL to serve as targets for cytotoxic T cells and as stimulators in one way mixed lymphocyte culture will be used to determine hyperbaric oxygen culture induced modification of the immunologic properties. The role of oxygen in MHC down regulation will be determined quantitatively by CELISA and Flow cytometry in vitro with the LCL and in vivo in a thyroid allograft system by substituting nitrogen or helium for oxygen. Similarly the temperature dependence of MHC down regulation and prolonged allograft survival will be determined both in vitro and in vivo. Finally, the ability of hyperbaric oxygen cultured thyroids to stimulate allograft rejection (CTL generation) in vivo will be examined using limiting dilution analysis. The information generated in parts one and two will be used to design HOC systems that preserve islet functional integrity, yet result in MHC class I molecule down regulation and prolonged allograft and xenograft survival.