Abstract:

Objective To study the expressions of interleukin?17（IL?17）and interleukin?23（IL?23）in the intestinal muco?
sa of BABL/C mice infected with Blastocystis hominis. Methods A total of 30 BABL/C mice were randomly divided into different
groups：an experimental group，an immunosuppressant group and a normal group. Each mouse of the experimental group and im?
munosuppressant group was administered intraperieneally with dexamethasone（2mg，gd，for 5 days）and one of the control group
was given physiological saline（0.2 ml）. In the experimental group，each mouse was infected with Blastocystis hominis（107 para?
sites per 0.5 ml）by the intragastric infusion method；in the immunosuppressant group and normal group，the mice were fed with
equal physiological saline. On the fifth day post?infection，the duodenum，jejunum，ileum and colon of the mice of the 3 groups
were taken out for the tissue section. The pathological changes of bowel mucosa were determined by HE staining，and the expres?
sions of IL?17 and IL?23 in different parts of bowel mucosa were determined by immunohistochemistry assay. Results The patho?
logical examinations showed intestinal mucosa had various degrees of inflammatory changes. The expressions of IL?17 and IL?23 in
the intestinal mucosa of the mice in the experimental group was significantly higher than those in the immunosuppressant group or
normal group（both P < 0.05）. The expressions of IL?17 and IL?23 in the intestinal mucosa of the mice in the immunosuppressant
group were similar to those in the normal group（P > 0.05）. The expression of IL?17 in the duodenum or jejunum or colon of the
mice was significantly higher than that in the ileum in the experimental group（ P <0.05）. The expression of IL?23 in the duode?
num or jejunum of the mice was significantly higher that that in the ileum or colon in the experimental group（P < 0.05）. Conclu?
sions IL?17 and IL?23 are highly expressed in the intestinal mucosa of the mice infected with Blastocystis hominis. IL?23 may al?
so be involved in the immunomodulatory effects of Blastocystis hominis infection，which plays a mutual regulatory role with IL?17.

Key words: Blastocystis hominis；Interleukin?17（IL?17）；Interleukin?23（IL?23）；Intestinal mucosa；Mouse

摘要：

目的观察人芽囊原虫（Blastocystis hominis）感染小鼠肠道组织中白细胞介素17（IL?17）和IL?23的表达情况。方法30只BABL/c小鼠随机分为实验组、免疫抑制剂组和对照组，实验组和免疫抑制剂组小鼠腹腔注射地塞米松2mg/只，日1次，连续5天；对照组小鼠腹腔注射生理盐水0.2 ml/只。实验组每鼠经口感染107个人芽囊原虫，免疫抑制组和对照组每鼠经口灌服0.5 ml生理盐水。感染人芽囊原虫5 d后，剖杀小鼠，分别取十二指肠、空肠、回肠和结肠制作成组织切片，HE染色检查小鼠肠黏膜病变，免疫组化法检测各肠黏膜中IL?17和IL?23的表达水平。结果HE染色显示，肠道黏膜有不同程度炎症改变。IL?17和IL?23在实验组小鼠不同肠黏膜中的表达均显著高于免疫抑制剂组和对照组（P < 0.05），而免疫抑制剂组与对照组IL?17和IL?23在小鼠不同肠黏膜中的表达差异无统计学意义（P > 0.05）。IL?17在实验组小鼠十二指肠、空肠、结肠黏膜中的表达水平均显著高于回肠黏膜（P < 0.05），IL?23在实验组小鼠十二指肠、空肠黏膜中的表达水平显著高于回肠和结肠黏膜（P < 0.05）。结论IL?17和IL?23参与人芽囊原虫感染的免疫反应，且IL?17与IL?23在人芽囊原虫感染的免疫应答过程中有一定的相互调节作用。

关键词: 人芽囊原虫；白介素17；白介素23；肠黏膜；小鼠