BALB/c小鼠感染弓形虫后Th1/Th2免疫漂移的实验研究  

The study on polarization of Th1 and Th2 immune responses in BALB/c mice infected with toxoplasma gondii

作　　者：李永念[1] 包怀恩[2] 

机构地区：[1]贵阳医学院免疫学教研室,贵阳550001 [2]贵阳医学院寄生虫学教研室,贵阳550001

出　　处：《中国免疫学杂志》2009年第3期209-212,共4页Chinese Journal of Immunology

基　　金：贵州省教育厅科研基金(F2006-6)资助

摘　　要：目的：动态分析BALB/c小鼠感染弓形虫后Th1/Th2免疫失衡及免疫漂移特点,并探讨转录因子T-bet和GA-TA-3在此过程中的改变及其意义。方法：90只BALB/c小鼠随机分为正常对照组30只,弓形虫感染组60只。于感染后奇数天每天处死感染组小鼠2只,对照组小鼠1只,采用ELISA法动态检测各组小鼠血清中IFN-γ和IL-4的水平,同时应用荧光定量PCR方法检测小鼠脾细胞中T-bet和GATA-3 mRNA的表达情况。结果：感染组小鼠中,血清IFN-γ于感染后第4天开始显著升高,第5~7天维持在高峰值,从第8天开始下降,第9天降至正常水平;IL-4于感染后第8天开始显著升高,第9天升至峰值,从第14天开始下降,第15天降至正常水平;脾细胞T-bet mRNA的表达在感染后第3天升高,第5天达高峰后于第9天降至正常水平;脾细胞GATA-3 mRNA的表达在感染后第7天升高,第11天达高峰,于第13天降至正常水平。正常对照组小鼠在实验期内IFN-γI、L-4水平没有明显变化,维持在正常的较低水平。结论：BALB/c小鼠感染弓形虫后诱导的免疫应答在感染急性期（第1~8天）以Th1应答为主,第9至13天,宿主免疫应答以Th2细胞应答为主,之后Th1/Th2应答基本恢复平衡。Th1应答向Th2应答的漂移与T-bet和GATA-3 mRNA的表达相关并受其调控,Th1/Th2型免疫应答的发生时相和效应强度可能影响弓形虫感染的最终结局。Objective：To explore the polarization of Th1 and Th2 immune response and the changes of transcription factor（T-bet and GATA-3） in BALB/c mice infected with toxoplasma gondii.Methods：Sixty BALB/c mice were infected with toxoplasma tachyzoite（1×104/m,0.5 ml） by intraperitoneal injection and thirty BALB/c mice only received an injection of same amount of normal saline as control.After injection,two mice of infection group and one mouse of control group were killed in odd number days.Then,the serum IFN-γ and IL-4 were measured by ELISA,and the mRNA expression of T-bet and GATA-3 in mice spleens were detected by Real-Time RT-PCR.Results：In the infection group of mice,the IFN-γ was remarkable increased at the fourth day and kept the peak from the 5th day to 7th day.Then,it decreased to normal level at 9th day postinjection;but IL-4 was remarkable increased at the 8th day and reached to the peak at 9th day.Then it decreased to normal level at 15th day postinjection.The mRNA of T-bet expression was increased at the third day and kept the peak from the 5th day to 7th day.Then,it decreased to normal level at 9th day postinjection.The mRNA of GATA-3 expression was increased at the 7th day and rised to the peak at 11th day.Then,it decreased to normal level at 13th day postinjection.There were not obvious changes of IFN-γ and IL-4 or T-bet and GATA-3 in normal mice.Conclusion：The Th1 immune response is dominant in acute infection when mice are infected by toxoplasma.Then it biases toward Th2 response at 9th day to 13th day postinfection.The shift of Th1/Th2 polarization influences the finale of toxoplasma infection.

关 键 词：BALB/C小鼠 弓形虫(刚地) TH1应答 Th2应答 

分 类 号：R382.5[医药卫生—医学寄生虫学]