肝脏器官维持自身环境稳定方面发挥重要作用。肝脏作为外周免疫器官具有产生免疫耐受的能力, 临床上人体肝移植较其它器官移植容易获得免疫耐受。DAP12-/-小鼠肝移植失去免疫耐受为探索诱导器官移植免疫耐受形成的分子机制提供了实验动物模型。以我们前期建立了以DAP12关联的免疫受体信号通路GFP报告细胞膜型为基础，建立同种异体小鼠肝移植模型和肝移植效果评价体系，从动物模型中提实验材料，应用流式细胞技术，基因表达芯片和DAP12免疫沉淀和蛋白质谱分析: 1)对比小鼠DAP12-/-和WT肝移植物中免疫细胞表型，免疫分子和DAP12信号通路相关分子基因表达的差异；2)筛选出DAP12信号通路上游受体分子及其配体分子的编码基因；3)将候选受体表达基因分别表达于DAP12-NATF-GFP细胞，筛选和发现其配体分子。确定DAP12信号通路上游分子为设计诱导器官移植免疫耐受和治疗自身免疫病的药物提供新思路

Liver immune system plays a crucial role in the regulation of liver internal and external immune response and the maintenance of self-homeostasis. As a peripheral immune organ, liver can induce immunologic tolerance. In clinical practice, it is easier to get tolerance for liver allograft, so we are going to investigate the allograft tolerance induction using mouse liver transplant model. The liver allograft tolerance can be reversed in DAP12 knock out mouse liver transplantation. It has already provided a reliable experimental base to find the molecular mechanism of DAP12 signing pathway to liver transplant tolerance. Firstly, we are going to make the allogeneic mouse liver transplant model and the evaluation system for liver transplantation outcomes, and obtain experimental materials from mouse models to reach the specific aims of our proposal by the methods of flow cytomtry, gene chips and immunoprecipitation with DAP12 signaling pathway fluorescent reporter (NATF-GFP) cell model. (1) To compare the differences of immune cells phenotypes, immune molecules and DAP12 signaling pathway related molecules between DAP12-/- and wild type mouse in liver transplantation; (2) To screen the coding genes of upstream receptors and their ligands in DAP12 signaling pathway; (3) To express several candidate receptor genes on NFAT-GFP cell line to verify our hypothesis and finding. If the upstream receptors and ligands of DAP12 signaling pathway are identified in liver allograft tolerance, it will provide new insights to design drugs and treatment schemes in organ transplant rejection and autoimmune diseases.