肺炎支原体感染小鼠Th1/Th2平衡状况及Tim-3 mRNA的表达

Expression of Tim-3mRNA and the balance of Th1/Th2 in mice infected with Mycoplasma pneumoniae

目的通过检测Tim-3mRNA的表达水平及IFN-γ、IL-4的含量,初步探讨肺炎支原体感染鼠Th1/Th2细胞的动态变化及Tim-3的免疫调控作用。方法通过滴鼻感染建立肺炎支原体肺炎小鼠模型,观察小鼠的一般状况,分别于感染后3d、5d、7d、14d、21d取材,应用RT-PCR方法检测肺组织和脾脏Tim-3mRNA的表达;采用ELISA法检测肺泡灌洗液中细胞因子IFN-γ、IL-4的含量。结果实验组IFN-γ于3d出现升高(t=2.309,P<0.05),5dIFN-γ开始下降,而IL-4于3d开始升高并一直持续到7d(t=6.436,P<0.05),之后逐渐恢复正常,肺组织和脾脏Tim-3mRNA的表达均于5d达到峰值(t=4.727,P<0.05;t=7.962,P<0.05),且肺组织和脾脏Tim-3mRNA表达量与IL-4呈正相关(r=0.561,P<0.05;r=0.462,P<0.05),从5d开始与IFN-γ呈负相关(r=-0.379,P<0.05;r=-0.431,P<0.05)。结论小鼠感染肺炎支原体后Th1/Th2失衡,以Th2介导的免疫反应为主;Tim-3可能参与了感染后对Th1细胞的负调控。

In this article, we study the expression of Tim-3 mRNA and the Thl/Th2 status in mice with Mycoplasma pneumoniae（Mp） pneumonia. The Mycoplasma pneumoniae （Mp） infection model was built by inhalation in BALB/c mice, and the general condition was observed. Tim-3 mRNA levels in lung tissue and spleen were determined by RT-PCR. The levels of IL-4 and INF-7 in BALF were measured by ELISA. The results showed that compared with control group, the IFN-7 level in the experimental group increased significantly at day 3 p.i. （P〈0.05） and gradually declined at day 5 p.i. （P^0.05）, but the IL-4 level in the experimental group increased significantly at day 3 p.i. and continued to the day 7 p.i. （P%0.05）. The expression of Tim 3 mRNA in lung and spleen were both the highest at day 5 p.i. （t=4. 727, P%0.05; t=7. 962, P%0.05）, and were positively correlated with IL 4 level （r= 0. 561, P%0.05; r= 0. 462, P%0.05）, but negatively correlated with INF 7 level from day 5 p.i. （r=-0. 379, P%0.05; r=-0. 431, P〈0.05）. In conclusion, after the infection of Mp, there was an imbalance of Thl/Th2 cells and Th2 cells dominated. Tim-3 might probably produce a negative regulatory against Thl cells af ter Mycoplasma pneumoniae infection, but its mechanism needs further study.