FGL2在泡球蚴感染所致DC细胞成熟中的作用研究

The role of FGL2 on DC maturation in mice in the late stage of infection with Echinococcus multilocularis

目的研究FGL2在泡球蚴感染所致DC细胞成熟中的作用及意义。方法 8~10周龄雌性野生型BALB/c小鼠12只和FGL2基因敲除小鼠12只,均随机分为2组:感染组6只,对照组6只。实验组腹腔注射0.1ml泡球蚴混悬液,对照组于相同部位注射等量PBS。感染后4个月将小鼠处死,取脾,制备脾细胞悬液,采用流式细胞术检测DC细胞成熟表面标记CD80及CD86的表达。留取血清,采用ELISA测定FG12水平。结果泡球蚴载量感染晚期fgl2-/-小鼠低于野生型小鼠,(F=8.426,P<0.05)。qRT-PCR检测泡球蚴感染晚期Em14-3-3mRNA表达,fgl2-/-小鼠低于野生型小鼠,(F=16.070,P<0.05);ELISA检测泡球蚴感染早期野生型小鼠和对照组血清FGL2,感染组高于对照组(F=13.995,P<0.05);流式细胞术检测泡球蚴感染小鼠腹腔细胞和脾脏细胞中CD11b+DC和CD11c+DC细胞CD80表达水平发现前者泡球蚴感染fgl2-/-小鼠晚期腹腔细胞中CD80表达水平显著高于野生型小鼠(F=236.303,P<0.05),后者在泡球蚴感染fgl2-/-小鼠晚期腹腔细胞和脾脏细胞CD80的表达水平均显著高于野生型小鼠(F=35.096,P<0.05);ELISA检测泡球蚴感染鼠中血清TNF-α水平发现泡球蚴感染fgl2-/-小鼠表达高于野生型小鼠(F=13.612,P<0.05)。结论在泡球蚴感染小鼠晚期,FGL2高表达可能参与泡球蚴感染引起的DC细胞成熟度降低及由此所致的免疫逃避有关。

Objective To study the role of FGL2 on DC maturation in mice in the late stage of infection with Echinococcus multilocularis. Methods Eight-to 10-week-old female C57/BL6（wild-type）and C57/BL6 fgl2^-/-mice were intraperitoneally injected with 100μl of a suspension of E.multilocularis metacestodes.Each experimental group included6 animals.Control mice received 100μl of PBS alone.Mice were sacrificed 4 months post-infection,and DC maturation markers CD80 and CD86 were measured using flowcytometry. Results The parasite load in the last stage of echinococcosis was lower in fgl2^-/-mice than that in WT mice（F=8.426,P〈0.05）.According to qRT-PCR,the expression of Em14-3-3 mRNA in the last stage of echinococcosis was lower in fgl2^-/-mice than that in WT mice.Levels of Em14-3-3 mRNA expression differed significantly（F=16.070,P〈0.05）.According to ELISA,serum FGL2 levels in the early stage of echinococcosis in WT mice were higher than those in the control group（F=13.995,P〈0.05）.Levels of CD80 expressed by CD11 b＋DCs and CD11 c＋DCs were detected via flow cytometry of abdominal cells and spleen cells of mice infected with E.multilocularis.The levels of CD80 expressed by CD11 b＋DCs,in the last stage of E.echinococcosis were markedly higher in fgl2^-/-mice than those in WT mice（F=236.303,P〈0.05）.The levels of CD80 expressed by CD11 c＋ DCs were also higher（F=35.096,P〈0.05）.According to ELISA,levels of TNF-αexpression were higher in fgl2^-/-mice than in WT mice infected with E.multilocularis（F=13.612,P〈0.05）. Conclusion High levels of FGL2 expression in the late stage of echinococcosis might play a key role in the decrease of DC maturation and related immune evasion by E.multilocularis.