IL-18基因导入对小鼠胶原诱导关节炎作用的研究

目的观察IL-18基因导入对小鼠胶原诱导性关节炎（CIA）的治疗作用。方法在CIA小鼠发病早期，将IL-18表达质粒pCAGGS-IL-18（pIL-18）经肌肉注射导入CIA小鼠体内，对照组给予空白质粒pCAGGS，3周后同量加强治疗1次。用关节炎评分评估CIA小鼠的病情，用组织学染色评价膝关节的软骨和骨破坏，用RT-PCR和real-time PCR法测定CIA小鼠髌骨及邻近滑膜组织的细胞因子及转录因子表达水平。结果与对照组相比，治疗组能有效抑制胶原诱导性关节炎小鼠的关节炎评分，阻止关节软骨破坏，虽然髌骨及邻近的滑膜组织IL-18的mRNA表达没有明显改变，但TNF-α及IL-17A的mRNA表达明显降低，IL-10的mRNA表达明显增加，同时，Th2型转录因子GATA-3的表达明显增高，Th2型转录因子T-bet及Th17型转录因子ROR-γt的表达无明显改变。结论与IL-18的细胞因子治疗不同，单独IL-18表达质粒的基因导入即可对CIA小鼠达到治疗作用。该作用通过提高GATA-3的表达，增加Th2型细胞因子IL-10，降低Th1型细胞因子TNF-α及Th17型细胞因子IL-17A的表达来实现。

Objective To investigate the effect of IL-18 gene therapy on murine collagen-induced arthritis（CIA）. Method CIA mice were injected with IL-18-expressing plasmid pCAGGS-IL-18（pIL-18）intramuscularly（i.m）. A booster injection was given with the same dosage in three weeks. Control group were injected with pCAGGS at the same dosage. The arthritis response was monitored visually by macroscopic scoring. Histology of knee was performed to assess the occurrence of cartilage destruction and bone erosion. RT-PCR（reverse transcription-polymerase chain reaction）and real-time PCR were employed to determine the mRNA expression of cytokine and transcription factors in patella with adjacent synovium in CIA mouse. Results Compared with control group,treatment groups showed a remission on macroscopic score and advancement of histology. Moreover,the mRNA levels of IL-17A and TNF-α,but not IL-10,were greatly inhibited both in the synovial tissue and in the articular cartilage in treatment group. Further analysis in the mechanism indicated that the expression of GATA-3 was significantly higher than that of T-bet and ROR-γt. Conclusion These data indicated that gene transfer of IL-18 suppressed the macroscopic score of CIA,which may be mediated not only by inhibiting inflammatory cytokines such as IL-17A and TNF-α,but also by inducing anti-inflammatory mediators such as IL-10. Moreover,the transcription factor of GATA-3 may play an important role on it.