小鼠首次感染RSV的年龄因素对成年后再次感染RSV时气道炎症的影响

Effects of the age of primary infection with RSV on airway inflammation after secondary RSV infection in adult mice

目的研究小鼠首次感染呼吸道合胞病毒(RSV)的年龄对成年后二次感染RSV时Th17/Treg平衡及气道炎症的影响。方法选取Balb/c小鼠,分为新生期感染组和断奶期感染组,每组36只。经两次RSV滴鼻造模后,第8周开始每隔1 d处死6只小鼠,造模完毕后取肺组织,采取流式细胞方法检测Th17和Treg细胞百分比、ELISA法检测IL-17浓度、Western blot法检测RORγt和F0XP3蛋白表达。结果RSV二次感染后第8天,新生期感染组小鼠肺组织Th17细胞百分比、RORγt表达以及IL-17浓度显著高于断奶期感染组(P<0.05),而肺组织Treg细胞百分比、FOXP3蛋白表达则明显低于断奶期感染组(P<0.05)。新生期感染组小鼠气道反应性明显高于断奶期感染组(P<0.05)。新生期感染组BALF中细胞总数、淋巴细胞、中性粒细胞和嗜酸性粒细胞数目均显著高于对照组(P<0.05)。结论新生期小鼠感染RSV可能加重成年后二次感染RSV时Th17/Treg平衡及气道炎症。

Objective To investigate the effects of the age of mice when primarily infected with respiratory syncytial virus(RSV)on Th17/Treg balance and airway inflammation after second infection of RSV in adult mice.Methods Balb/c mice were divided into a neonatal infection group and a weaning infection group(n=36).After twice RSV nasal dripping,6 mice were killed every other day at the eighth week.Then,lung tissue was taken,and the percentages of Th17 and Treg cells were detected by flow cytometry.ELISA was used to detect IL-17 concentration,while Western blot was used to detect the levels of RORγt and F0XP3 protein.Results The neonatal infection group presented remarkable increases in the percentage of Th17 cells,RORγt expression and IL-17 concentration in lung tissues,as well as marked decreases in the percentage of Treg cells and F0XP3 expression,compared to the weaning infection group(P<0.05).Substantially enhanced airway reactivity was found in the neonatal infection group,compared to the weaning infection group(P<0.05).The total number of cells,lymphocytes,neutrophils and eosinophils in BALF were significantly higher in the neonatal infection group than those in the control group(P<0.05).Conclusions RSV infection in neonatal mice may aggravate Th17/Treg balance and airway inflammation in secondary RSV infection in adult mice.