ToxoDB#17型弓形虫感染小鼠引起小肠潘氏细胞溶菌酶缺失

Deficiency of Paneth Cells Lysozyme in Small Intestine of Mice Infected by ToxoDB#17 Strain Toxoplasma gondii

为探究Toxo DB#17型弓形虫对昆明小鼠小肠潘氏细胞(Paneth cells,PCs)溶菌酶的表达及小肠病理损伤特点,该研究以8周龄小鼠为研究对象,灌胃1×106个Toxo DB#17型弓形虫卵囊,分别在灌胃后6 HAI(hours after inoculation)、1 DAI(day after inoculation)、3 DAI、8 DAI取小肠各段,常规方法制作石蜡切片,HE和免疫组化染色,研究小肠病理损伤、虫体分布、潘氏细胞及溶菌酶表达特点。结果显示,小鼠弓形虫感染率为100%,弓形虫虫体抗原分布随时间延长呈增多趋势(P<0.05),小肠的病理损伤随着弓形虫感染时间的延长,未见明显变化。小肠隐窝数、含潘氏细胞隐窝数、PCs总数和颗粒总数的变化总趋势呈现先减少后增加再减少的趋势,3 DAI数量较多(P>0.05),潘氏细胞颗粒未观察到溶菌酶阳性染色反应。以上结果表明,Toxo DB#17型弓形虫抑制潘氏细胞溶菌酶的表达,对肠道损伤较轻,潘氏细胞及其分泌颗粒对弓形虫有应答反应,溶菌酶的缺失与Toxo DB#17型弓形虫成功入侵肠道有关。

In order to investigate the small intestine pathological lesions and the change of Paneth cells（PCs） lysozyme after infection of Toxo DB#17 strain Toxoplasma gondii, 1×106 Toxo DB#17 strain T. gondii oocysts were fed to Kunming mice orally. Pathological lesions and the distribution of T. gondii in small intestine, Paneth cells and expression of lysozyme were observed on 6 hours after inoculation（HAI）, 1, 3 or 8 days after inoculation（DAI） by HE and immunohistochemical staining, respectively. The results showed that 100% of the mice fed with 1×106 oocysts were infected. The positive area of T. gondii in the intestine was increased with prolonged infection time（P〈0.05）, but the lesions did not change significantly. The number of crypts, crypts containing PCs, PCs and granules in intestine were decreased firstly, then increased, decreased last. They were the highest at 3 DAI, compared to the control group（P〉0.05）. It was negative staining of lysozyme in granules of PCs after infection of T. gondii. These results indicated that Toxo DB#17 strain T. gondii infection caused the deficiency of the Paneth cells lysozyme in intestine of mice. The pathological lesions of Toxo DB#17 strain T. gondii on small intestine of mice were lightly. PCs and their granules had responded to T. gondii. The deficiency of lysozyme in PCs may have relation with succeed invasion intestine of T. gondii.