不同纲(罗非鱼/大鼠)肝细胞移植中的细胞免疫反应

背景:由于人肝细胞来源困难,许多学者尝试异种肝细胞移植的研究.文献报道较多的是猪肝细胞,受体多为大鼠、豚鼠等,这些均属于哺乳纲内不同目或科动物之间的移植.不同纲动物间的肝细胞移植报道较少.目的:将罗非鱼肝细胞植入大鼠脾内,探讨不同纲动物间肝细胞移植的细胞免疫排斥反应机制.方法:以胶原酶冷消化法分离罗非鱼肝细胞,以生理盐水重悬,细胞浓度调整为2×1010 L-1.将36只SD大鼠按随机数字表法分为移植组和对照组.对照组脾内注射生理盐水,实验组脾内移植罗非鱼肝细胞.在移植后4,8,24 h,3,5d,各组分别处死2只大鼠,以苏木精-伊红染色法观察移植物组织学变化,免疫组织化学SABC法检测移植物周围大鼠CD4,CD8阳性细胞.结果与结论:移植后数小时即发生排斥反应,8 h后受体脾内很难见到正常肝细胞.移植后4 h移植物周围可见CD4和CD8阳性细胞聚集.提示罗非鱼肝细胞移植到大鼠脾内数小时诱发了排斥反应,细胞免疫参与其中,自然杀伤细胞可能具有重要作用.

Cell-mediated immune response of tilapia-to-rat hepatocyte xenotransplantation

BACKGROUND: Many scholars attempt to xenotransplantation because of shortage of human donor hepatocytes. In the field of hepatocyte xenotransplantation, two different mammalian species, i.e., pig-to-rat, and pig-to-rodent, are much reported. Hepatocyte transplantation between two different classes has been rarely reported. OBJECTIVE: To investigate the mechanisms of cell-mediated immune response in hepatocytes xenotransplantation between tilapia and rat. METHODS: The tilapia (donor) hepatocytes were isolated by collagenase cold digestion and adjusted to 2×107 /mL using physiological saline. Thirty-six SD (recipient) rats were randomly divided into transplantation and control groups (n = 18). Rats from the control group received injection of physiological saline into the spleen, and those from the transplantation group received injection of tilapia hepatocytes. At each time point (4 hours, 8 hours, 24 hours, 3 days, and 5 days) after transplantation, two rats were respectively sacrificed for histological changes examination using hematoxylin-eosin staining and detection of CD4+/CD8+ lymphocytes surrounding the grafts using immunohistochemical SABC method. RESULTS AND CONCLUSION: The transplanted hepatocytes were rejected a few hours after transplantation. Surviving hepatocytes in spleens were hardly seen 8 hours after transplantation. The aggregation of CD4+CD8+ lymphocytes was detected surrounding the grafts 4 hours after transplantation. These findings suggest that tilapia hepatocytes transplantation into rat spleen induces rejection within a few hours, cell-mediated immune response is involved in the rejection of hepatocytes xenotransplantation, and natural killer cells may play an important role in this kind of rejection.