旋毛虫感染对胶原诱导性关节炎小鼠肠道菌群的影响

EFFECTS OF TRICHINELLA SPIRALIS INFECTION ON INTESTINAL FLORA OF COLLAGEN-INDUCED ARTHRITIS MICE

寄生蠕虫能否通过调节宿主肠道菌群进而改善炎症性疾病是近年的研究热点。为探讨旋毛虫感染对胶原诱导性关节炎(Collagen-Ⅱinduced arthritis,CIA)小鼠肠道菌群构成和丰度的影响,将15只小鼠随机分为正常对照组、关节炎(CIA)组和预先感染旋毛虫关节炎(CIA.TS)组,在首次胶原诱导后第50 d,取小鼠粪便进行16S rDNA测序,然后将CIA组和对照组之间的差异菌属与关节炎评分进行Spearman相关分析。结果显示,与对照组相比,CIA组小鼠菌群结构发生了明显的改变,其丰富度和多样性有上升趋势;在门水平上,脱铁杆菌门、变形菌门和梭杆菌门的丰度明显增加;在属水平上,未分类毛螺菌科、Mucispirillum属和脱硫弧菌属的丰度明显增加,Alistipes属和理研菌属的丰度明显减少。CIA组小鼠中丰度显著升高的菌属,其相对丰度与关节炎评分呈正相关;而丰度显著降低的菌属,其相对丰度与关节炎评分呈负相关。与CIA组相比,预先感染旋毛虫的关节炎小鼠(CIA.TS)菌群的丰富度和多样性有下降趋势,脱铁杆菌门和变形菌门的丰度明显减少,Mucispirillum属和脱硫弧菌属的丰度明显减少,理研菌属的丰度明显增加。以上结果表明,CIA小鼠肠道菌群结构改变与关节炎疾病严重程度密切相关,而预先感染旋毛虫可缓解CIA小鼠的关节炎症,其改善作用可能与调节CIA小鼠肠道菌群结构有关。

There has been increasing attention on the research whether helminth infection attenuates inflammatory diseases by regulating host intestinal flora. To investigate the effects of Trichinella spiralis infection on intestinal flora of Collagen-induced arthritis(CIA) mice, 15 mice were randomly divided into 3 groups, including the normal mice(Control), mice with collagen Ⅱ-induced arthritis(CIA) and mice infected with T. spiralis prior to immunization with collagen Ⅱ(CIA.TS). Spearman correlation analysis of arthritic score and different bacterial genera between CIA and control group were performed at day 50 after Collagen Ⅱ immunization based on high-throughput sequencing of the 16 S rDNA gene of the intestinal flora. The results showed that the flora structure of the CIA group was significantly changed. As compared with Control group, CIA group had an elevating trend in the richness and diversity, and the relative abundance of Deferribacteres, Proteobacteria, Fusobacteria significantly increased at the phylum level, and the relative abundance of unidentified_Lachnospiraceae, Mucispirillum, Desulfovibrio significantly increased,while the relative abundance of Alistipes, Rikenella significantly decreased at the genus level. And the correlation analysis showed that the relative abundance of the genus significantly increased in CIA mice was positively correlated with arthritic score, while the relative abundance of the genus significantly decreased in CIA mice was negatively correlated with arthritic score. However, compared with the CIA group, CIA.TS group had a decreasing trend in the richness and diversity, and the relative abundance of Deferribacteres and Proteobacteria significantly decreased, and the relative abundance of Mucispirillum and Desulfovibrio significantly decreased, the relative abundance of Alistipes significantly increased. In conclusion, the changes of intestinal flora structure in CIA mice were closely related to the severity of arthritis, and pre-infection with T. spiralis may relieve joint inflammation in CIA mice, and its improvement may be related to the regulation of intestinal flora structure in CIA mice.