BALB/c小鼠急、慢性弓形虫感染时Th细胞应答的基因表达谱分析

The study of the gene expression spectrum for Th cell immune response in acute and chronic toxoplasma infection in BALB/c mice

目的:分析弓形虫感染BALB/c小鼠后诱导Th细胞应答的基因表达谱特征。方法:以刚地弓形虫速殖子感染BALB/c小鼠,分别于感染后第6天和第12天各处死小鼠2只,制备小鼠脾细胞悬液并混合,提取细胞总RNA。采用基因芯片技术检测小鼠Th细胞应答各相关基因的表达情况,并对部分表达变化的基因应用Realtime-PCR予以验证。结果:BALB/c小鼠感染弓形虫后,基因芯片检测共有20种基因表达差异超出2倍以上。感染后第12天比第6天,8种基因(Gata-3、Ccr3、Ccr4、Bcl6、Nfatc1、CD80、Fos、CD69)表达上调,12种基因(T-bet、CIITA、Irf1、Mapk9、Nfatc3、Fasl、Tyk2、Lat、Mapk10、Socs3、Socs6、Yy1)表达下调。总体呈现Th2型免疫应答基因上调,Th1型免疫应答基因呈下调趋势。Gata-3和T-bet基因的Realtime-PCR检测结果与基因芯片检测一致。结论:从基因表达谱分析来看,BALB/c小鼠感染弓形虫后在感染急性期以Th1细胞应答为主,度过急性期后以Th2细胞应答为主。

Objective： To study the gene expression spectrum of Th cell immune response in acute and chronic toxoplasma infection in B ALB/c mice.Methods： BALB/c mice were infected with toxoplasma tachyzoite （1 × 10^4/m, 0.5 ml） by intraperitoneal injection. Two mice were killed at 6th and 12th day postinjection. The immune response gene expressing levels in mice spleen cells were detected with 128 kind gene microarray chips. Partial of the results were determined with Real time-PCR. Results：There were 20 genes changed after toxoplasma infection. Eight of them （Gata-3, Ccr3, Ccr4, Bcl6, Nfatc1, CD80, Fos, CD69 ） were regulated upward and twelve genes （T-bet, CIITA, Irf1, Mapk9, Nfatc3, Fasl, Tyk2, Lat, Mapk10, Socs3, Socs6 and Yy1 ） were regulated downward. On the whole, expression of Th2 response genes presented a up trend, and Th1 response genes presented a down trend. The results of Real time-PCR were accordant with microarray in the expression of Gata-3 and T-bet gene. Conclusion：According to the Th cell immune response gene expression spectrum, Thl immune response is dominant in the acute infention when mice are infected by toxoplasma. Then, it is biased toward Tn2 immune response.