神经介素B及其受体NMBR参与抗A型流感病毒H1N1亚型感染的信号通路

The Signaling Pathway of Neuromedin B and Its Receptor NMBR Involvement in Anti-influenza A Virus H1N1 Subtype Infection

NMB/NMBR通过调节A型流感病毒(IAV/H1N1/PR8)感染诱导的细胞因子表达而参与抗IAV的先天性免疫反应。为探究其发挥抗IAV/H1N1感染的信号通路,本文用PR8和WSN毒株分别感染MLE-12细胞和小鼠,用NF-κB抑制剂BAY11-7028单独或联合NMB处理MLE-12细胞,小鼠后腿肌内注射NMB和NMBRA,采用RT-PCR和qRT-PCR分析NMB、NMBR、IL-6、IFN-α和NP基因表达变化,采用Western blot分析NMB、NMBR、P65/p-P65、IκBα和NP蛋白表达的变化。结果显示,BAY11-7028可促使PR8和WSN感染的MLE-12细胞中NMB、NMBR、IL-6和IFN-α基因表达水平均下降和NP基因表达水平上升,并降低NMB、NMBR和p-P65蛋白表达水平和提升IκBα和NP蛋白表达水平。然而,NMB联合BAY 11-7028诱导PR8或WSN感染后的细胞中IL-6和NP表达出现极显著下降和IFN-α显著上升。此外,NMB抑制PR8和WSN感染的小鼠肺组织内p-P65和NP蛋白表达水平和促进IκBα蛋白表达水平;NMBRA联合NMB抵消NMB对PR8或WSN感染后的这些蛋白表达水平的调节作用。综上表明,NMB/NMBR通过调节PR8和WSN感染的MLE-12细胞和小鼠体内的NF-κB信号通路上P65蛋白磷酸化和IκBα的表达,进而影响下游细胞因子IL-6和IFN-α基因的表达,从而发挥抗IAV/H1N1感染的先天性免疫应答反应。

NMB/NMBR had been involved in anti-influenza A virus(IAV/H1N1/PR8)infection by regulating the expression of cytokines.To explore the signaling pathway of NMB/NMBR against IAV/H1N1 infection,the MLE-12 cells and mice were infected with IAV/H1N1 subtype PR8 or WSN strain respectively,and the cells were treated with NF-κB inhibitor BAY11-7028 alone or in combination with NMB,meanwhile,the mice were injected with NMB or NMBRA.The expression profiles of NMB,NMBR,IL-6,IFN-αand NP genes in transcript levels were analyzed by the methods of RT-PCR and qRT-PCR,and the expression profiles of NMB,NMBR,P65/p-P65,IκBαand NP in protein levels were analyzed by Western blot.The results showed that the decreased expression levels of NMB,NMBR,IL-6 and IFN-α,and increased NP levels in MLE-12 cells after PR8 or WSN infection were induced by BAY11-7028 treatment.Meanwhile,the significantly decreased expression levels of NMB,NMBR and p-P65 proteins,and increased expression levels of IκBαand NP proteins were also induced by BAY11-7028.However,NMB combined with BAY11-7028 could induce a significant decrease in IL-6 and NP,and a significant increase in IFN-αin MLE-12 cells after PR8 or WSN infection.NMB could inhibit the expression of p-P65 and NP proteins,and promoted the expression level of IκBαprotein in lung tissues of PR8 and WSN infected mice.NMBR inhibitor NMBRA combined with NMB could counteract the regulatory effects of NMB on the expression of these proteins after PR8 or WSN infection.These results suggest that NMB could regulate the phosphorylation of P65 protein and the expression of IκBαinvolved in NF-κB signaling pathway in PR8 or WSN infected MLE-12 cells and mice,and affect the expressions of downstream cytokines,IL-6 and IFN-α,thereby play the innate immune response against IAV/H1N1 infection.