摘要
目的:探讨不同疟原虫感染DBA/2小鼠的免疫应答特点。方法:DBA/2小鼠经腹腔注射致死型约氏疟原虫(P.y17XL)和夏氏疟原虫(P.c AS)感染的红细胞,计数红细胞感染率;ELISA动态检测感染小鼠脾细胞培养上清中IFNγ-和IL-4水平;采用RT-PCR动态检测脾细胞中Th1和Th2型转录因子T-bet和GATA3 mRNA表达量。结果:两种疟原虫感染小鼠在感染早期T-bet mRNA表达量均明显增加,升高幅度明显高于GATA3,T-bet/GATA3比值明显高于感染前水平;IFNγ-明显升高后伴随IL-4分泌水平增加。但是,P.c AS感染小鼠IFNγ-水平明显高于P.y17XL感染小鼠,且随后的IL-4水平仅出现短暂升高,感染后前8天T-bet/GATA3比值未有明显下降趋势,原虫血症逐渐升高至小鼠全部死亡。相比,P.y17XL感染小鼠T-bet/GA-TA3比值在感染后第3天达峰值,随后缓慢下降但仍高于对照组,原虫血症得到控制至小鼠自愈。结论:抗疟保护性免疫不仅依赖于Th1和Th2型免疫应答的有效建立和协调过渡,而且Th1/Th2型免疫应答的发生时相和效应强度可能影响着疟疾感染的最终结局。
Objective： To investigate differences of the immune of the responses in DBA/2 mice infected with different strains of malaria parasites.Methods： DBA/2 mice were infected by intraperitoneal injection with 1 × 10^6 virulent P.yoelii 17XL-or P. chabaudi AS-parasitized erythroeytes, and then the ratio of RBC infected was counted. Splenocyte IFN-γ and IL-4 producing levels were measured by ELISA. The mRNA expression of T-bet and GATA3, which were Th1 type transcriptional factor and Th2 type transcriptional factor respectively, were measured dynamically by RT-PCR. Results： The expression of T-bet mRNA in beth P. y17XL and P. c AS infected mice increased and was higher than that of GATA3, the ratio of T-bet/GATA3 increased significantly in early phase of infection. Both mouse strains showed significant elevation in IFN- γ production followed by significant increase of IL-4 production. In addition, IFN-γ production was much higher in P. c AS-infected mice than in those infected by P. yoelii 17XL which was followed by a momentary increase of IL-4 production. The ratio of T-bet/GATA3 had no trend to decrease until day 8 post-infection（PI）. Finally, P. c AS infected mice died with increased parasitemia. In contrast, the ratio of T-bet/GATA3 in P. y17XL-infected mice reached a peak on day 3 PI, and then declined but still kept in a higher level than that in control group. P. y17XL infected mice survived with declined parasitemia. Conclusion： The protective immunity against malaria infection depends on the establishment of effective Thl and Th2 responses and a successful switch of immune response from Thl to Th2. The phase and level of immune response might affect the final outcome of malaria infection.
出处
《中国免疫学杂志》
CAS
CSCD
北大核心
2008年第6期496-499,共4页
Chinese Journal of Immunology
基金
辽宁省教育厅资助项目(2004D108)
辽宁省教育厅资助项目(05L547)
