石仙桃多糖对肺炎支原体感染模型小鼠Th1/Th2细胞因子表达的影响

Effect of polysaccharide of Pholidota chinensis Lindl. on the expression of Th1/Th2 cytokines in mice infected with Mycoplasma pneumoniae

目的探讨石仙桃多糖对肺炎支原体肺炎模型小鼠的肺泡灌洗液(BALF)中γ-干扰素(IFN-γ)、肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-12等细胞因子表达的影响。方法采用配对设计随机方法将90只BABL/C裸鼠分为三组:模型组、克拉霉素组和石仙桃多糖组,每组30只。用PPLO肉汤培养基培养肺炎支原体,将成功培养的肺炎支原体滴入裸鼠鼻腔1×107CCU/mL菌液各50μL(1、5、8 d)。造模第9天开始,石仙桃多糖组用石仙桃多糖干预,克拉霉素组按15 mg/kg剂量灌胃给药,连续6 d,模型组灌胃等体积的生理盐水。干预1、3、6 d后,分别收集小鼠BALF,用SP4琼脂平板定量培养BALF肺炎支原体,采用酶联免疫吸附测定(ELISA)法测定小鼠BALF中IL-1β、IL-12、IFN-γ、TNF-α等细胞因子水平,肺部组织用中性甲醛固定HE染色,观察肺炎支原体感染小鼠肺的病变程度。结果与模型组比较,石仙桃多糖组BALF定量培养肺炎支原体菌落数量明显减少(P<0.05),肺部炎症明显好转,肺组织病理学评分和肺实质炎症评分明显下降(P<0.05或P<0.01)。治疗第1、3、6天,石仙桃多糖组IL-1β、IL-12、IFN-γ、TNF-α水平较模型组明显降低,差异均有统计学意义(P<0.05)。结论石仙桃多糖显著减轻肺炎支原体肺炎小鼠肺部炎症,其机制可能与降低肺炎支原体肺炎模型小鼠体内Th1/Th2细胞因子IL-1β、IL-12、IFN-γ和TNF-α的表达有关。

Objective To investigate the effects of polysaccharide of Pholidota chinensis Lindl.on the expression ofγ-interferon(IFN-γ),tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,IL-12 and other cytokines in bronchoalveolar lavage fluid(BALF)of model mice of Mycoplasma pneumoniae pneumonia.Methods By matched pair design random method,ninety BALB/c nude mice were randomly divided into three groups:model group,Clarithromycin group and polysaccharide of Pholidota chinensis Lindl.group,with 30 mice in each group.PPLO broth medium was used to cultivate mycoplasma pneumonia,the successfully cultivated Mycoplasma pneumoniae was dropped into the nasal cavity of nude mice 1×107 CCU/mL bacteria solution,each 50μL(1,5,8 d).From the ninth day of modeling,polysaccharide of Pholidota chinensis Lindl.group was started to be use polysaccharide of Pholidota chinensis Lindl.,Clarithromycin group was given 15 mg/kg of Clarithromycin by intragastric administration,continued for 6 d,the model group was given same volume of normal saline by gavage.After intervention for 1,3,6 d,the mice BALF was collected,SP4 agar plate was used to cultivate BALF Mycoplasma pneumoniae quantificationally,enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of IL-1β,IL-12,IFN-γ,TNF-α.Lung tissue was fixed with neutral formalin to take HE staining.The pathological degree of mice infected by Mycoplasma pneumoniae was observed.Results Compared with model group,the number of bacterial colonies of Mycoplasma pneumoniae cultivated by BALF quantificationally in polysaccharide of Pholidota chinensis Lindl.group was reduced significantly(P<0.05),the pulmonary inflammation was improved significantly,and the scores of lung pathology and pulmonary parenchyma were decreased significantly(P<0.05 or P<0.01).After treatment for 1,3,6 d,the levels of IL-1β,IL-12,IFN-γ,TNF-αin polysaccharide of Pholidota chinensis Lindl.group were significantly lower than those of model group,the differences were statistically significant(P<0.05).Conclusion Polysaccharide of Pholidota chinensis Lindl.can significantly reduce the pulmonary inflammation of mice with Mycoplasma pneumoniae pneumonia,the mechanism may be related to reduce the expression of Th1/Th2 cytokines of IL-1β,IL-12,IFN-γ,TNF-αin model mice with Mycoplasma pneumoniae pneumonia.