日本血吸虫感染对OVA诱导的小鼠过敏反应的影响

目的研究蠕虫感染对过敏性哮喘的影响。方法将15只BALB/c小鼠随机分成3组,每组5只。Ⅰ组为血吸虫感染后OVA致敏组,Ⅱ组为单纯OVA致敏组,Ⅲ组为正常对照组。Ⅰ组小鼠首先建立日本血吸虫感染模型,于感染后第57~84d,与Ⅱ组小鼠一起以OVA(卵清白蛋白)诱导建立过敏性哮喘模型,第85d剖杀全部小鼠,收集脾脏、肺脏和支气管肺泡灌洗液。制备支气管肺泡灌洗液涂片以计数其中各类细胞;制备肺组织切片以检查肺部病理变化;培养脾细胞以检测培养上清中相关细胞因子水平。另外,还要检测支气管肺泡灌洗液中相关细胞因子水平。结果与Ⅱ组相比,Ⅰ组小鼠肺部嗜酸粒细胞数量显著减少(P<0.05),肺部炎症明显减轻(P<0.05),支气管肺泡灌洗液和脾细胞培养上清中IL-4和IL-5水平均降低(P<0.05),而IFN-γ水平无明显改变(P>0.05)。结论日本血吸虫感染对OVA诱导的过敏性哮喘有抑制作用。

Influence of Schistosoma japonicum infection on OVA -induced allergic reaction of mice

In order to study the influence of helminth infection on allergic asthma, 15 BALB/c mice were divided into three groups randomly. In group 1, mice were Schistosoma japonicum-infected and OVA-treated; in group 2, mice were treated with OVA only, and in group 3, mice without any treatment were taken as control. Firstly, the mice in group 1 were infected with Schistosoma japonicum; and then, from day 57 to day 84 after infection, mice in group 1 and group 2 were immunized and challenged with Ovalbumin(OVA) together to induce allergic asthma. On day 85, all the mice in three groups were killed, and spleens, lungs and bronchoalveolar lavage fluids(BALF) were collected. BALF smears were prepared for counting differential cells; lung tissue sections were prepared for examining pulmonary pathological changes, and splenocytes were cultured for measuring relevant cytokines in supernatants of the culture. Besides these, relevant cytokines in BALF were also detected. The results showed, compared with the mice in group 2, the eosinophils infiltrated in the lung of the mice in group 1 decreased dramatically(P<0.05), and pulmonary inflammation diminished markedly(P<0.05). Moreover, the levels of IL-4 and IL-5 in both BALF and supernatants of splenocyte culture reduced(P<0.05), while the levels of IFN-γ did not change evidently(P>0.05). All these results indicate that Schistosoma japonicum infection has inhibitory effect on OVA-induced allergic asthma.