DEN-2 NGC株感染BALB/c小鼠TH1/TH2类细胞因子产生的差异

The study for the dynamic levels of TH1/TH2 cytokines in the BALB/c mice infected with dengue type 2 virus NGC strain

目的：通过观察2型登革病毒（DEN2）NGC株初次感染和再次感染BALB／c小鼠后小鼠血浆中TH1和TH2类细胞因子的产生及其动态变化，研究DEN2感染的免疫机制。方法：用不同量的DEN2NGC株经皮下多点注射，建立BALB／c小鼠感染模型，间接ELISA法测定感染后不同时间小鼠血浆IL-2、IFN-γ、IL-4、IL-5、IL-6、IL-10的含量。结果：（1）在初、再次感染阶段，DEN2 NGC株各感染组产生IL-4、IFN-γ、IL-2、IL-5、IL-6、IL-10与正常对照组有显著差异（P〈0．05）。①在初次感染阶段，NGC株各感染组血浆IL-2、IL-5、IL-6于第4、6、8天出现；在再次感染阶段，各感染组产生IL-2、IL-5、IL-6均于第1天迅速升高；IL-2水平于第4天达高峰（104448．46±13314．1pg／ml），维持5—7天后迅速下降；IL-5于48小时达到高峰（135．125±46．75pg／ml）；各组小鼠IL-6产生的动态相似，在再次感染后第1天，达高峰（555．823±44．639pg／ml）后逐渐下降。②初次感染早期，IL-4水平明显升高，而IFN-γ处于较低水平；再次感染后第1天，IL-4水平达最高峰（4294．668±349．038pg／ml），IFN-γ则于第4天和第11天达较高水平，两者的产生彼消此长，且产生动态与感染病毒量有关。（2）在初、再次感染阶段，用不同量DEN2 NGC株感染组产生细胞因子水平有差异。结论：DEN2 NGC株初次和再次感染BALB／c小鼠后，TH1和TH2应答均可发挥一定作用，二者相互影响，TH细胞及其产生的CK在DEN感染的发病机制中起重要作用。

Objective： To observe the dynamic levels of TH1/TH2 eytokines from the plasma of BALB/c mice infected with DEN2 NGC strain and research immune response mechanism. Methods： The BALB/e mice plasma samples collected from different experiment groups at various time after infection were tested for IL-2 ,IFN-γ,IL-4 ,IL-5, IL-6 and IL-10 levels with indirect ELISA. Results：（ 1 ）The BALB/c mice could produce IL-2, IFN-γ, IL-4, IL-5, IL-6 and IL-10 after DEN2 infection and the correlation of eyto- kines with normal group（P 〈0. 05）. ①The eytokines that appeared were IL-2 on the fourth day,IL-5 on the sixth day,and IL-6 on the eighth day after DEN2 infection;In the reinfection phase,IL-2 appeared on the first day with a rapid peak on the fourth day（ 104 448.46 ± 13 314. 1 pg/ml） and then declined quickly after 5 to 6 days;IL-5 appeared on the first day and reached a peak（ 135.. 125 ±46. 75 pg/ml） ;IL-6 appeared on the first day with a peak on the 48 h（55. 823 ±44. 639 pg/ml）. ②Tbe dynamic levels of IL-4 and IFN-γ/in the plasma of BALB/c mice infected with DEN2 NGC strain were different. The levels of IL-4 were significantly increasing after DEN2 infection while that of IFN-γ/were lower：IL-4 reached a peak on the first day（4 294. 668 ± 349. 038 pg/ml） and then the levels of IFN- γ/higher on the forth and eleventh day. （2）The concentrations of eytokines produced by infected animals had been.closely associated with the doses of DEN2. Conclusion：Both Thl and Th2 responses are induced by DEN2 and play a role;while,Th2 response is more predominant than Thl response. Th cell and Th-related cytokines are importance with DEN infective diseases.