负显突变体细胞因子信号转导抑制物-1增强干扰素-γ体外抗柯萨奇病毒活性

Dominant-Negative Suppressor of Cytokine Signaling 1 Enhancement on Antiviral Activity of Interferon-Gamma against Coxsackie B_3 Virus in Vitro

目的病毒性心肌炎(VM)细胞模型JAK/STAT1信号通路的特异性内源抑制物细胞因子信号转导抑制物-1(SOCS1)及其负显突变体SOCS1(dnSOCS1)对IFN-γ抗CVB3活性影响。方法构建pEGFP-C1-SOCS1及pEGFP-C1-dnSOCS1的真核表达载体,以脂质体法转染至心肌细胞后,加用IFN-γ刺激细胞并感染病毒,采用荧光显微镜检测心肌细胞中SOCS1和dnSOCS1表达,同时利用Westernblot法测定不同条件下STAT1表达水平并测定病毒滴度。结果与转染dnSOCS1组比较,转染SOCS1组病毒滴度高,而心肌细胞存活率低,心肌细胞搏动时间短。另外在dnSOCS1组磷酸化STAT1的表达更明显。结论dnSOCS1可增强IFN-γ体外抗病毒活性。SOCS1可为我们治疗VM提供一个新的治疗靶点。

Objective To observe the effect of interferon-gamma(IFN-γ) on antiviral activity in rat cardiomyocytes infected with CVB_3 through transfecting the intrinsic JAK/STAT inhibitor, the suppressor of cytokine signaling 1(SOCS1) or the dominant-negative SOCS1(dnSOCS1). Methods The SOCS1 or dnSOCS1 DNA fragment was inserted into a green fluorescent protein fusion vector, which was then transfected into the rat cardiomyocytes with lipofectamine 2000, subsequently, IFN-γ stimulated the cells then CVB_3 was infected. The expression of SOCS1 and dnSOCS1 was observed by the fluorescent microscope. Western blot was used to study the protein of Phospho -STAT1 in different groups.Results Virus titer was higher in the SOCS1 transfected group than in dnSOCS1 group( P <0.05). Compared with SOCS1 group,in dnSOCS1 group the Phospho-STAT1 was more obviously,the myocardocytes beat rhythmically longer.Conclusions dnSOCS1 could enhance the antiviral activities of IFN-γ in vitro. SOCS1 may be the new therapeutic target in the viral myocarditis.