脂多糖对约氏疟原虫感染DBA/2小鼠感染早期的免疫调节作用  

Regulatory effect on lipopolysaccharide for lethal Plasmodium yoeliiinfection in early stage

作　　者：李莹[1] 刘军[1] 潘艳艳[1] 王各各[1] 延娟[1] 郑丽[1] 冯辉[1] 曹雅明[1] 

机构地区：[1]中国医科大学基础医学院免疫教研室,沈阳110001

出　　处：《中国人兽共患病学报》2011年第11期975-979,共5页Chinese Journal of Zoonoses

基　　金：国家自然科学基金项目(No.30800961)资助

摘　　要：目的本文主要探讨脂多糖(LPS)在致死型约氏疟原虫(Plasmodium yoelii 17×L,Pyl7×L)感染早期的调节作用。方法 6～8w、雌性DBA/2小鼠,随机分为实验组和对照组,经腹腔接种1×106 Pyl7XL寄生的红细胞。实验组于感染后d2静脉给予LPS(25μg/只)。动态观察两组小鼠的原虫血症水平,小鼠脾脏树突亚群及其表面TLR4和活化T细胞的表达水平。结果 (1)两组小鼠于感染后约d15均自愈,LPS处理组小鼠的原虫血症水平在感染后d5-8显著低于对照组;(2)与对照组相比,在感染后d3和d5,LPS处理组小鼠脾脏DCs亚群表达水平显著升高,在感染后d3,TLR4表达水平显著升高。在感染后d5,LPS处理组小鼠脾脏细胞培养初始活化T表达水平显著升高。结论在P.y17×L感染早期,LPS可通过激活TLR4强化DC成熟进一步强化Th1免疫应答反应,降低原虫血症,这将为疫苗的开发提供新的靶点。This paper discusses the immune regulatory mechanism of the TLR4 agonist-lipopo in 6 to 8 weeks lysaccharide（LPS） in the lethal form of Plasmodium yoelii infection in early stage.Female DBA/2 mice were randomly divided into experimental and control groups,intraperitoneally inoculating 1×106 Plasmodium yoelii 17×L（Pyl7×L） parasitized red blood cells.The experimental group was given LPS（25μg/once） intravenously after infection day 2.Parasitemia were dynamicly observed during the whole infection course.In infected day 0,day 3,and day 5,the number of changes of dendritic cell subsets,dendritic cell surface TLR4,and activation on the effect of T cells in the spleen were detected by flow cytometry（FACS）.Results demonstrated that the level of parasitemia in LPS treatment mice after infection day 5 to day 8 was significantly lower than that in the control group;on day 3 and day 5 post infection,compared with the control group,the number of CD11c＋CD11b＋DCs and CD11c＋CD45R/B220＋DCs subsets in the spleen in LPS treated mouse were significantly increased;on day 3,CD11c＋TLR4＋ DCs in the spleen were significantly increased;on day 5,CD4＋CD69＋T lymphocytes in the spleen were significantly increased.In conclusion,through the activation of TLR4 in early stage of P.y17×L infection,LPS could promote the DC maturation,change its subpopulation proliferation model,and further strengthen the establishment of Th1-type immune response.Then it obviously decreases the parasitemia.Therefore it would provide new targets for effective antimalarial vaccine development.

关 键 词：脂多糖 致死型约氏疟原虫 免疫调节 

分 类 号：R328.3[医药卫生—人体解剖和组织胚胎学]