猪蛔虫感染对小鼠肺部免疫病理反应的动态观察

Dynamic Observation of Pathological Immune Response in Lungs of Mice Infected with Ascaris Suum

目的:动态观察感染猪蛔虫后,小鼠肺组织的病理变化及肺泡灌洗液中相关细胞因子的变化,从而了解蛔虫感染对肺脏的侵害过程。方法:温箱孵育猪蛔虫受精卵至含蚴卵,用灌胃法感染小鼠,分别在感染后第0、7、14、45天处死小鼠,观察肺组织的病理改变,并通过ELISA方法检测肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中IL-4、IFN-γ、IL-10和TGF-β_1含量的动态变化。结果:感染14天组,肺组织的病理改变最为严重:大量炎症细胞浸润,嗜酸性粒细胞增多,严重者支气管狭窄,肺泡塌陷;感染45天组,小鼠肺组织病理变化比前者显著减轻。BALF中IL-4含量在感染7天、14天后分别为(169.20±34.61pg/ml),(381.33±57.39pg/ml),均明显高于未感染组(38.03±6.09 pg/ml);在感染45天后降低(98.49±25.33 pg/ml),但仍高于未感染组。IL-10水平在感染后降低;但感染45天组,IL-10水平却有所增高(179.78±21.33 pg/ml),并高于感染前。IFN-γ、TGF-β_1含量在感染后也有明显降低。结论:猪蛔虫感染初期,小鼠肺部损伤严重,小鼠BALF中促炎症细胞因子占主导地位;但在感染后期,BALF中促炎症细胞因子含量降低,炎症抑制因子IL-10有所增高,炎症缓和。

Objective： To understand the pathological and immunologic changs of lung in the different times when experimental mice were infected Asearis suum. Methods： Fertilized eggs of Ascaris suum were incubated to Infection stage in the incubator at 37℃. Then, Balb/c mice were infected intragastrically. After infection, the mice were sacrificed respectively on days 0, 7, 14, 45. Lung tissues were sliced and HE stained for histological examination under electromicroscop; and the level of IL-4, IFN-γ , IL-10 and TGF-β1, in bronehoalveolar lavage fluid （BALF） from each group were determined by enzyme-linked immunosorbent assay （ELISA）. Results： The pathological change of lungs from mice, which were sacrificed in day 14, is the most serious： peribronchial and perivascular numerous inflammatory cells, granulocytosis, bronchostenosis and alveoli pulmonis collapse; but the state tend to alleviated on day 45 after infection. The level of IL-4 in BALF from mice which were sacrificed on day 7 （169.20± 34.61pg/ml）, 14 （381.33± 57.39pg/ml）, were significantly increased compared with other groups. As an inhibitory factor, IL-10 level in BALF from mice which were sacrificed on day 0, 7, 14, 45 were respectively 111.43± 8.42, 71.07± 16.97, 63.12± 18.06 and 179.78± 21.33pg/ml; The level of IL-10 in BALF was significantly degraded at the start of infection, and was increased in the period of late infection. TGF-β1 , level in BALF was also decreased markedly after infection. Conclusions： The inflammatory reaction of lungs from mice is the most serious during the early ascaris suum infection, the pro-inflammatory cytokines dominates in BALF of mice, but decreasing in the late stage of infection,and inhibition of inflammatory cytokine IL-10 has increased and inflammation has been eased.