脾内途经的肝脏靶向性基因治疗中Kupfier细胞的抗原提呈作用

目的探讨肝脏Kupffer细胞(KC)在脾内途径的肝脏靶向性基因治疗中的抗原提呈作用及可能机制。方法以结肠癌肝转移小鼠为模型，以脾内移植GM-CSF基因修饰的胎肝细胞(FILC-GM)与低剂量IL-2、5-Fu腹腔注射作为基因治疗与化学免疫治疗联合应用方案。结果荷瘤小鼠治疗后2w，整个肝小叶KC数目均扩增；KC对99mTc-亚锡植酸钠吞噬功能明显增强；与KC抗原提呈功能和活化T细胞功能密切相关的共刺激分子CD40虽在对照组KC中有基础性表达，但在基因治疗联合化学免疫治疗组中，其表达水平皆有不同程度的上调；此外，联合治疗后KC体外能有效诱导同种T细胞增殖反应，细胞因子IL-12和IL-12的分泌水平亦升高，并且这些反应能被抗CD40L抗体所封闭。结论脾内途径的肝脏靶向性基因治疗能有效提高KC的抗原提呈功能，CD40/CD40L分子在其中发挥了重要的共刺激作用。

The effect On the antigen-presenting function of Kupffer cells by liver-targeting gene therapy

The evidernce that Kupffer cells (KC) are capable of controlling metastatic growth in the liver is largely circumstantial.However,the ability of KC to function as antigen-presenting cells was not much studied.Thus,the aim of this study was to characterize the effect on the antigen-presenting function of Kupffer cells by intrasplenic transplantation of GM-CSF gene-modified fetal liver cells (FLC-GM)in combination with IL-2 and 5-Fu.Two weeks after the tumor-bearing mice was treated,strong increase in KC numbers and percentage of phagocytosis of 99m Tc within the liver tissue were observed.At the same time,co-stimulator antigen CD40 expression on KC were determined by fluorescence-activated cell sorter(FACS)and found that its expression level was upregulated.In addition,OVA-specific autogenetic T cells mixed lymphocyte reaction induced by KC have increased.Moreover,we observed that blocking CD40/CD40L interaction with anti-CD40L mAbs caused significantly inhibition of T cell proliferation response and inhibition of IL-2 and IL-12 production.These results indicated that intrasplenic transplantation of GM-CSF gene therapy in combination with immuno-chemotherapy could efficiently activate the KC immunologic function, particularly its antigen-presenting function.