Sema4D对RSV所致哮喘大鼠Th1/Th2的免疫调节及咳喘宁口服液的干预作用

Immunomodulatory effect of Sema4D on Th1/Th2 in asthmatic rats induced by RSV and intervention of Kechuanning oral liquid

目的:探讨脑信号蛋白4D(semaphorin 4D,Sema4D)对呼吸道合胞病毒(respiratory syncytial virus,RSV)所致哮喘大鼠Th1/Th2的免疫调控及咳喘宁的干预作用。方法:60只SPF级Wistar大鼠随机分为10组,即正常组,模型组,Sema4D组,Sema4D抗体组,咳喘宁低、中、高剂量组,以及Sema4D+咳喘宁低、中、高剂量组。除正常组外,其余各组采用RSV合并卵清蛋白(ovalbumin,OVA)诱导大鼠哮喘模型。HE染色观察肺组织病理变化;ELISA法检测支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中炎症因子白细胞介素4(interleukin-4,IL-4)、IL-6、IL-8、肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)和干扰素γ(interferon-γ,IFN-γ)的含量。结果:HE染色结果显示,模型组、Sema4D组及Sema4D+咳喘宁低剂量组大鼠肺组织均有明显的炎症细胞浸润和炎性损伤,而Sema4D抗体组,咳喘宁低、中、高剂量组,以及Sema4D+咳喘宁中、高剂量组的这些病理变化明显减轻。与正常组相比,其余各组BALF中IL-4、IL-6、IL-8和TNF-α的含量显著升高,IFN-γ的含量显著降低(P<0.05或P<0.01);与模型组相比,Sema4D组IL-4、IL-6、IL-8和TNF-α的含量升高,IFN-γ的含量降低(P<0.05或P<0.01),Sema4D抗体组,咳喘宁低、中、高剂量组,以及Sema4D+咳喘宁低、中、高剂量组IL-4、IL-6、IL-8和TNF-α的含量显著降低(P<0.01),IFN-γ的含量显著升高(P<0.05或P<0.01);与咳喘宁低、中、高剂量组相比,Sema4D抗体组及Sema4D+哮喘宁中、高剂量组的上述指标均无显著差异(P>0.05)。结论:Sema4D可引起Th1/Th2免疫失衡,加重哮喘;抑制Sema4D表达可减少炎症因子的产生,调节Th1/Th2平衡;咳喘宁可能通过干预Sema4D,减轻RSV所致哮喘大鼠的免疫炎症,从而达到治疗哮喘的效果。

AIM:To explore the effect of semaphorin 4 D(Sema4D)on the immune regulation of Th1/Th2 in asthmatic rats induced by respiratory syncytial virus(RSV)and the effect of Kechuanning(KCN)intervention on the asthmatic rats.METHODS:Healthy SPF female Wistar rats(n=100)were randomly divided into 10 groups:normal group,model group,Sema4D group,Sema4D antibody group,low,middle and high doses of KCN groups,and Sema4D+low,middle and high doses of KCN groups. Except the rats in normal group,the other rats were treated with RSV combined with ovalbumin(OVA)to induce asthmatic model. The pathological changes of the lung tissue were observed by HE staining,and the levels of interleukin-4(IL-4),IL-6,IL-8,tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ)in bronchoalveolar lavage fluid(BALF)were measured by ELISA.RESULTS:Inflammatory cell infiltration and inflammatory damage in lung tissues of the rats in model group,Sema4D group and Sema4D+low dose of KCN group were observed by HE staining,while these pathological changes were attenuated in Sema4D antibody group,low,middle and high doses of KCN groups,and Sema4D+middle and high doses of KCN groups. Compared with normal group,the levels of IL-4,IL-6,IL-8 and TNF-α in BALF of the rats in the other groups were significantly increased,and the level of IFN-γ was significantly lowered(P<0. 05 or P<0. 01). Compared with model group,the levels of IL-4,IL-6,IL-8 and TNF-α in Sema4D group were increased,and the content of IFN-γ was decreased(P<0. 05 or P<0. 01). Compared with model group,the levels of IL-4,IL-6,IL-8 and TNF-α in Sema4D antibody group,low,middle and high doses of KCN groups,and Sema4D+low,middel and high doses of KCN groups were significantly decreased(P<0. 01),while the content of IFN-γwas significantly increased(P<0. 05 or P<0. 01). No significant difference among Sema4D antibody group,Sema4D+middle and high doses of KCN groups,and low,middle and high doses of KCN groups was observed(P>0. 05).CONCLUSION:Sema4D causes Th1/Th2 immune imbalance and aggravates asthma. Inhibition of Sema4D reduces the production of inflammatory factors and regulates the balance of Th1/Th2. KCN may attenuate RSV-induced immune inflammation of asthmatic rats by inhibiting Sema4D,so as to achieve the anti-asthma effect.