香菇多糖对约氏疟原虫感染BALB/c小鼠Th1型应答的调节作用

目的探讨香菇多糖(Lentinan,Lent)对致死型约氏疟原虫(Plasmodium yoelii 17XL,Py17XL)感染BALB/c小鼠Th1型细胞免疫应答的调节效应。方法对Py17XL感染的BALB/c小鼠进行不同时间点的Lent预处理,动态观察用药后各组感染小鼠原虫血症水平和生存率;于感染后第0d、1d、3d和5d分别提取小鼠脾细胞,ELISA法检测脾细胞培养上清中IL-12、IFN-γ的分泌水平,Griess反应检测脾细胞培养上清中一氧化氮(NO)含量。结果与药物未处理组相比,感染前15d 1mg/kg Lent用药组显著降低感染小鼠的原虫血症水平,提高生存率;明显增强Th1型免疫应答中关键细胞因子IL-12、IFN-γ的分泌水平,并提高NO含量。结论Lent预处理能够有效激发Py17XL感染的BALB/c小鼠Th1型细胞免疫应答的建立,提示调控免疫应答对于致死型约氏疟原虫感染早期免疫防御的重要性。

Lentinan has a regulatory effect on Th1 type immune response for BALB/c mice infected with Plasmodium yoelii

In order to investigate the regulatory effect of Lentinan(Lent) on Th1 type immune response during BALB/c mice infected with virulent Plasmodium yoelii 17XL(Py17XL),BALB/c mice were treated with Lent in different time(15d,6d,and 0d before infection).Then the mice were infected by intraperitoneal injection with 1×106 virulent Py17XL parasitized erythrocytes,parasitemia and survival rate were dynamic observed during the whole infection course.IL-12,IFN-γ production from the splenocyte supernatants were determined by ELISA.And the levels of NO were checked by Griess reaction.The results showed that,compared with Lent-untreated group,the mice treated with Lent 15d before infection could obviously decrease the parasitemia and all the mice survived this infection.The secretion of IL-12 and IFN-γ,which are the necessary cytokine for Th1 type immune response,also increased significantly.The level of NO production was elevated,too.Therefore,we concluded that Lent pre-treated could help the set-up of Th1 type immune response efficiently during the BALB/c mice infected with Py 17XL.These results indicated that the regulation of immune response is important for host against virulent malarial infection during early stage.