新生期小鼠卡介苗接种和呼吸道合胞病毒感染对肺部炎症和免疫状态的影响

The impact of neonatal Bacillus Calmette-Guerin vaccination on lung inflammation and immune status of mice with respiratory syncytial virus infection

目的研究小鼠新生期卡介苗(BCG)接种对呼吸道合胞病毒(RSV)感染后肺部炎症和免疫状态的影响。方法新生BALB/c小鼠分4组:A组为对照组、B组为BCG接种组、C组为RSV感染组、D组为BCG接种后RSV感染组。RSV感染后1周观察肺泡灌洗液(BALF)中白细胞数及分类,ELISA法检测BALF中IFN_γ、IL_4、IL_10含量,RT_PCR检测肺组织Toll样受体4(TLR4)mRNA表达,HE染色进行肺组织炎症病理评分。结果C、D两组BALF中白细胞总数、淋巴细胞数、中性粒细胞数、IFN_γ含量以及肺组织TLR4mRNA表达量和炎症病理评分显著高于A、B组(P<0.01或0.05),BALF中IL_4、IL_10含量4组间差异无显著性,C、D两组之间在各项指标上差异无显著性。结论小鼠新生期BCG接种对RSV感染诱发的肺组织炎症和免疫状态无影响。

Objective To study the impact lung inflammation and immune status of mice of neonatal Bacillus Calmette-Guerin （BCG） vaccination on with respiratory syncytial virus （RSV）infection. Methods Neonatal BALB/ c mice were divided into four groups. Group A was control. Group B was BCG-vaccinated only. Group C was RSV-infected only. Group D was BCG-vaccinated and RSV-infected. One week after RSV infection, bronchoalveolar lavage （BAL） was performed. BALF cells were counted and differentiated. BALF IFN-γ, IL-4 and IL-10 levels were detected by ELISA and lung TLR4 mRNA expression was analyzed by RT-PCR.Lung inflammation was scored after HE staining. Results Compared with group A and B, BALF total white cells, lymphocytes, neutrophils and IFN-γ concentration and lung TLR4 mRNA expression and inflammatory scores were significantly higher （P〈0.01 or 0.05） in group C and D. No differences were observed in BALF IL-4 and IL-10 levels between the four groups. There were no significant differences in all parameters between group C and D. Conclusions Neonatal BCG vaccination had no influence on RSV infection-related Thl-type cytokine response, increased TLR4 mRNA expression and pulmonary inflammatory infiltration.