Objective: To investigate the immunoregulatory effect of VitaminE( VE) on BALB/c mice infected with Plas modi urn yoelii 17XL(P. y17XL). Methods: Female 6 - 8-week-old BALB/c mice were randomly divided into two groups. Mice were orally administered VE 10 days before P. y17XL infection, once a day. Parasitemia was monitored by light microscope examination of Giemsa stained thin (tail) blood smears. We tested the subsets of splenic dendritic cells (DCs) : CDllc+ CDllb + myeloid DCs (mDCs) and CDllc+CD45RVB220 + plasmacytoidDCs (pDCs), the expressions of Toll-like receptor 9 (TLR9) in CDllc+ DCs, the percentage of macrophages and CD4+ CD69 + T cells on day 3, 5 post infection ( p. i. ) by flow cytometry. Results: (1) Pretreatment with VE increased the parasitemia and the mortality rate was 70% on day 6 ( p. i) , but the control group was only 30% . (2) the subsets of splenic DCs and the number of F4/80+ macrophages was significantly reduced in VE group; meanwhile, the activation of CD4+ T cells was declined on day 5 ( p. i) . Conclusion: VE pretreatment aggravate the progress of the malaria infection by inhibiting the mature and differentiation of DCs during the early stages of P. y17XL infection.%目的:探讨维生素E(Vitamin E,VE)对致死型约氏疟原虫(Plasmodium yoelii 17XL,P.y17XL)感染BALB/c小鼠的免疫调节效应.方法:6~8周、雌性BALB/c小鼠,随机分为实验组和对照组,经腹腔接种1×106 P.y17XL寄生的红细胞,实验组于感染前10天口服给予VE预处理.动态观察两组小鼠的原虫血症水平;流式细胞术检测感染后第0、3和5天脾树突状细胞(Dendritic cells,DCs)亚群和Toll样受体9(Toll like receptor,TLR9)表达水平、以及巨噬细胞和活化T细胞的表达数量.结果:(1)与正常感染组相比较,补充VE加重感染小鼠的原虫血症水平,死亡率于感染后第6天达到70%,而正常感染组在感染后第6天死亡率只有30%;(2)与正常感染组相比,在每一检测点,VE处理组小鼠脾脏DCs亚群表达水平显著降低;同时,F4/80+巨噬细胞数量明显低于对照组,在感染后第5天,VE处理组小鼠脾脏T细胞活化水平显著降低.结论:在P.y17XL感染早期,VE预处理可通过抑制DCs的成熟和分化,从而加剧P.y17XL感染BALB/c小鼠的感染进程.
展开▼
