ASL在抗仙台病毒先天免疫Ⅰ型干扰素表达信号通路中的作用

Role of ASL in innate immunity type Ⅰ interferon expression signal pathway against Sendai virus

目的 Ⅰ型干扰素在抗病毒先天免疫中发挥着重要作用,本研究探究尿素循环关键酶精氨基琥珀酸裂解酶(argininosuccinate lyase, ASL)在仙台病毒(Sendai virus, SeV)感染诱导Ⅰ型干扰素表达信号通路中的作用。方法 通过在HEK-293T细胞中过表达和敲低ASL,免疫印迹检测对SeV感染诱导IRF3磷酸化的影响;荧光素酶实验检测ASL过表达对SeV感染诱导Ifnb与Ifna4启动子活性的影响。结果 SeV感染诱导ASL表达水平升高;ASL过表达抑制SeV感染诱导的IRF3磷酸化,ASL敲低促进SeV感染诱导的IRF3磷酸化;荧光素酶实验揭示,ASL过表达抑制SeV感染诱导的Ifnb与Ifna4启动子活化。结论 ASL抑制SeV感染诱导的Ⅰ型干扰素信号通路的表达。

Type Ⅰ interferons play an important role in antiviral innate immunity. Argininosuccinate lyase(ASL), a key component of urea cycle, catalyzes argininosuccinate cleavage to generate arginine and fumarate. The study was performed to investigate the effects of ASL gain-of-function or loss-of-function on type Ⅰ interferon production signaling pathway in response to Sendai virus(SeV) infection. Western blot was used to detect the expression and phosphorylation of interferon regulatory factor 3(IRF3), one of the most important IRFs which control the transcription of IFN-β. Data showed that after virus infection, ASL expression was up-regulated;and ASL overexpression inhibited the phosphorylation of IRF3 whereas ASL knockdown led to enhanced IRF3 phosphorylation in response to SeV infection. Dual luciferase reporter assays revealed that ASL over-expression inhibited SeV infection-induced activation of Ifnb and Ifna4 promoters. In conclusion, ASL inhibits SeV infection-induced expression of type Ⅰ interferon signaling pathway.