摘要
目的探讨β1转化生长因子(TGF-β1)在猬迭宫绦虫(Spirometra erinacei)裂头蚴感染小鼠皮下肌肉组中的表达情况及意义。方法对采自野生王锦蛇(Elaphe carinata)的裂头蚴进行形态学观察和PCR检测。昆明小鼠80只,用数字随机表法挑选40只,雌雄各半作为实验组,剩余40只为对照组。用蛇源裂头蚴经口喂饲实验组小鼠,5条/鼠。于喂饲后第7、14、28、56天各随机剖杀10只,分别收集含有裂头蚴寄生的皮下肌肉组织,用中性甲醛固定,制作石蜡切片。HE染色后,观察裂头蚴感染病灶周围的病理变化和纤维化程度;免疫组化检测皮下肌肉中TGF-β1的含量变化。对照组不喂饲裂头蚴,检测时间及方法同实验组。结果PCR扩增获得约400 bp的目的条带。测序结果显示,该裂头蚴COX1基因与Gen Bank中的猬迭宫绦虫序列一致性为99.12%。HE染色检查,皮下肌肉中的裂头蚴被炎性囊壁所包裹,虫体与囊壁之间形成穴腔,穴腔有时出现少许的浆液或血液。囊壁最里面的区域有薄层的纤维蛋白、坏死的碎片,壁中早期以中性粒细胞浸润为主,也有嗜酸粒细胞、巨噬细胞、浆细胞等,随着病程的进展,炎性囊壁逐渐扩大,壁中以慢性炎性细胞浸润为主,囊壁周围是宿主的组织细胞,纤维结缔组织增生明显,并有不同程度的纤维化。免疫组化检查结果显示,TGF-β1的主要表达部位为裂头蚴周围的炎症反应带和纤维结缔组织增生部位。TGF-β1相对表达量在感染后逐渐增高,于感染第28天达峰值(0.654 5±0.045 5),第56天时明显下降。在感染后第7~56天,实验组的TGF-β1水平为(0.502 6±0.008 2)^(0.346 8±0.030 4)与同期对照组的(0.270 0±0.001 6)^(0.274 0±0.005 1)比较,差异均有统计学意义(P<0.05)。结论小鼠感染猬迭宫绦虫裂头蚴早、中期,TGF-β1表达水平均提高,其免疫抑制作用不利于清除和控制皮下肌肉组织中的裂头蚴。
Objective To investigate the dynamic expression of transforming growth factor β1(TGF-β1) in subcutaneous muscles of mice infected with Spirometra erinacei and its implication in control of the disease. Methods Morphological observation and PCR detection were performed on the larvae collected from wild Elaphe carinata. A total of 80 Kunming mice (20-25 g) were equally divided into experiment group and control group. Mice in the experiment group were each orally infected with 5 plerocercoids, while those in the control group were not infected. On days 7, 14, 28, and 56 after infection, 10 mice from each group were sacrificed and specimens of the subcutaneous muscle tissues containing pleroceroids were collected, fixed in formaldehyde, and paraffin sections prepared. HE staining was performed to observe pathological alterations and the degree of fibrosis at lesion-surrounding sites. Immunohistochemistry was performed to detect TGF-β1 in subcutaneous muscles. Results PCR resulted in specific COX1 bands of 400 bp, which showed a sequence similarity of 〉 99% with Spirometra erinacei. HE staining showed that the plerocercoids were packed by inflammatory cysts, and caverns were formed between plerocercoids and the cyst wall, with occasional appearance of serum or blood in the cavern. There were thin layers of fibrous protein and necrotic fragments inside the cyst wall. Early cyst walls were mainly invaded by neutrophils, eosinophils, macrophages, and plasmocyte. There was an enlargement of inflammatory cyst wall following the disease progression. There was a significant fibrous connective tissue hyperplasia and different degrees of fibrosis between the cyst wall and subcutaneous tissue. Immunohistochemistry showed that TGF-β1 was mainly expressed in inflammatory zones surrounding the plerocercoids and around focal fibrous hyperplasia. The level of TGF-β1 increased with time, reached a peak (0.654 5 ± 0.045 5) at 28 days post-infection, and decreased obviously at 56 days (0.346 8 ± 0.030 4). The TGF-β1 levels during days 7-56 post infection ranged from (0.502 6 ± 0.008 2) to (0.346 8 ± 0.030 4), which were all significantly higher than the control [(0.270 0 ± 0.001 6)-(0.274 0 ± 0.005 1)] (P 〈 0.01). Conclusion The expression of TGF-β1 increases in the early and middle stages of infection. The immune inhibition effect of TGF-β1 is disadvantageous for clearing and control of plerocercoids in subcutaneous muscle tissues.
出处
《中国寄生虫学与寄生虫病杂志》
CAS
CSCD
北大核心
2017年第3期270-273,279,共5页
Chinese Journal of Parasitology and Parasitic Diseases
基金
贵州省科技厅社会发展攻关项目(No.2014SY3024)~~
关键词
猬迭宫绦虫
裂头蚴
Β1转化生长因子
HE染色
免疫组织化学
Spirometra erinacei
Plerocercoid
Transforming growth factor β1
HE staining
Immunohistochemistry