新生隐球菌感染小鼠肺泡巨噬细胞相关细胞因子与疾病病程相关性研究

Correlation study on macrophage-derived cytokines and disease course in Cryptococcus neoformans infection mouse model

目的通过检测新生隐球菌感染小鼠巨噬细胞相关细胞因子的表达水平,探讨其在感染小鼠疾病病程的作用。方法应用单侧小鼠鼻孔接种感染新生隐球菌建立小鼠吸入感染隐球菌模型,在感染后第1、4、7、11、14、18、21天,PAS染色观察小鼠肺组织病理变化,并通过RT-PCR检测相应时间点小鼠巨噬细胞内相关细胞因子(IL-6、IL-8、TGF-β、TNF-α)的表达。结果小鼠吸入感染隐球菌后,PAS染色发现第4天肺内散在分布隐球菌,第7天可见肉芽肿形成,第11天大量炎性细胞浸润,第14天见肉芽肿内大量隐球菌,第18天隐球菌分布至全肺,第21天肺组织大量坏死;RT-PCR结果显示TGF-β和IL-6的表达在感染后14天达到最高值,然后逐渐降低,其中TGF-β升高幅度更为明显。结论在新生隐球菌感染小鼠中,TGF-β参与了机体的抗真菌免疫,在调节炎症反应方面有重要作用。

Objective We detected the expression of macrophage-derived cytokines in macrophage of Cryptococcus neoformans infection mouse model to explore the role of those cytokines in pathogenesis of infection mouse. Methods A mouse model of Cryptococcus neoformans infection was established by inhalation of Cryptococcus neoformans through one nostril. On day 1,4,7, 11,14,18,21 after inoculation,the infected lung were observed by histopathological analysis. Macrophage-derived cytokines（IL-6、IL-8、TGF-β、TNF-α）were detected by RT-PCR. Results Histopathological examination showed few Cryptococcus neoformans dis-tributed in lung on 4 days and granuloma formation on 7 days after infection. There were significant inflammatory cellular infiltration in the lung tissue on 11 days and a large number of Cryptococcus neoformans in granuloma on 14 days after infection. At 18 and 21 days,diffuse distribution of Cryptococcus neoformans in the lung and the lung necrosis were observed. The mRNA expression of TGF-βand IL-6 reached to the peak at 14 days,then decreased gradually. Conclusion TGF-βwas involved in regulating the anti-fungal immunity in Cryptococcus neoformans infection mouse.