乙型流感病毒感染过程中干扰素介导的天然免疫应答

Innate immune response mediated by interferon during influenza B virus infection

目的 探讨乙型流感病毒(influenza B virus,IBV)感染引起干扰素(interferon,IFN)介导的天然免疫应答。方法以IBV感染犬肾上皮细胞(MDCK)为模型,通过荧光定量PCR法检测IFN信号通路的激活以及IFN刺激基因的表达。收集IBV感染MDCK细胞36及48 h上清,与新鲜培养基混合培养IBV感染MDCK细胞,qPCR法检测内源性IFN的抗病毒作用。加入JAK-STAT通路抑制剂CP后,收集IBV感染MDCK细胞上清,培养IBV感染MDCK细胞,通过qPCR法检测JAK-STAT通路抑制后对内源性IFN抗病毒作用的影响。结果 IBV可有效激活IFN信号通路,并诱导产生Ⅰ型IFN(IFNα、IFNβ)以及Ⅲ型IFN(IFNλ1、IFNλ3)为主的细胞因子。同时,IBV感染MDCK细胞后可诱导产生一系列具有广谱抗病毒作用的IFN刺激基因(IFN-stimulated genes,ISGs),如ISG15、CCL5、CXCL10、MX1、RIG-I。用JAKSTAT通路抑制剂CP抑制该信号通路后,IBV感染MDCK细胞所诱导生成的ISGs的能力及其相应的抗病毒作用均被显著抑制。结论 IBV感染MDCK细胞可有效激活Ⅰ型及Ⅲ型IFN介导的JAK-STAT信号通路,本研究为进一步了解IBV与宿主的相互作用关系提供了参考。

Objective To explore the innate immune response mediated by interferon(IFN) induced by influenza B virus(IBV)infection.MethodsThe activation of IFN signaling pathway and the expression of IFN-stimulated genes were detected by qPCR using Madin Darby canine kidney(MDCK)cells infected with IBV as model.The supernatants of MDCK cells infected with IBV for 36 h and 48 h were collected and mixed with fresh medium to culture MDCK cells infected with IBV.The antiviral effect of endogenous IFN was detected by qPCR.After adding JAK-STAT pathway inhibitor CP,the supernatant of IBV infected MDCK cells was collected and the cells were cultured.The effect of JAK-STAT pathway inhibition on the antiviral effect of endogenous IFN was detected by qPCR.ResultsIBV effectively activated IFN signal pathway and induced the production of cytokines dominated by typeⅠIFN(IFNα,IFNβ)and typeⅢIFN(IFNλ1,IFNλ3).Meanwhile,MDCK cells infected with IBV induced a series of IFN-stimulated genes(ISGs)with broad-spectrum antiviral effect,such as ISG15,CCL5,CXCL10,MX1 and RIG-I.After CP was used to inhibit JAK-STAT pathway,the ability of ISGs production induced by IBV infection in MDCK cells and the corresponding antiviral effect were significantly inhibited.ConclusionMDCK cells infected with IBV effectively activated type Ⅰ and type Ⅲ IFN mediated JAK-STAT signaling pathways,which provided a reference for the further understanding the interaction between IBV and host.