中文摘要：

目的观察约氏疟原虫子孢子能否诱导DC成熟,并探讨其机制。方法GM-CSF常规诱导小鼠骨髓前体细胞,获得足量的DC,然后,解剖按蚊唾液腺子孢子与DC共培养,分别于2、4和24 h后,荧光显微镜下观察子孢子与DC的相互关系,同时采用流式细胞分析技术检测DC表面的MHC-Ⅱ类分子、CD80和CD86共刺激分子的表达情况,最后转染重组pFLAG-CMV8-CSP质粒后24 h,检测DC表面的共刺激分子的表达情况。结果在共培养后2h,子孢子便逐渐向DC迁移甚至黏附于DC表面;4 h后部分子孢子便进入DC且仍然保持子孢子的弯月形形态;24 h后DC内的部分子孢子逐渐变圆,类似肝期裂殖体的形态。流式检测发现共培养2 h后对DC共刺激分子表达无明显影响,而共培养4 h和24 h后DC共刺激分子的表达均上调。转染pFLAG-CMV8-CSP重组质粒至DC中后同样能诱导DC的共刺激分子的表达上调。结论在体外共培养的情况下,大部分子孢子可以主动侵入DC而少部分可以被DC吞噬,主动入侵DC的子孢子可能是通过其表面的CSP由纳虫空泡进入胞浆内后诱导DC成熟。

英文摘要：

In this paper,we observe the interaction of Plasmodium yaelii sporozoites with bone marrow-dendritic cells,and investigate whether sporozoites could induce DC maturation.Dendritic cells（DCs） were induced by GM-CSF from mouse bone marrow in vitro,and co-cultured with sporozoites dissected from Plasmodium yoelii-infected Anopheles stephensi.Different time later,the interaction betwoen the DCs and sporozoites were observed under fluorescence microscope：at 2 h,sporozoites were found to be adhered on DCs;at 4 h,most sporozoites were found to be inside the DCs and keep its fusiform shape;at 24 h,most sporozoites were observed in DCs and transformed into spherical EE（early erythrocytic stage）-like forms.Although the expression of costimulatory molecules （MHC-Ⅱ,CD80,CD86） on DCs was not affected as early as 2 h,sporozoites significantly up-regulated the expression of costimulatory molecules on DCs after 4 h and 24 h incubation with DCs.Interestingly,transfection of recombinant plasmid pFLAG-CMV8-CSP alone could also induce the expression of costimulatory molecules on DCs.The results showed that most sporozoites can actively entry into DC and induce DC maturation in vitro,while CSP might play an important role in DC maturation induced by sporozoites.