In order to breed new birds with strong disease resistance, it is necessary to first understand the mechanism of avian antiviral response. Interferon regulatory factor 7 (IRF7) is not only a member of type I interferons (IFNs) regulatory factor (IRFs) family, but also a major regulator of the IFN response in mammals. However, whether IRF7 is involved in the host innate immune response remains unclear in poultry, due to the absence of IRF3. Here, we first observed by HE stains that with the increase of the time of ALV-J challenge, the thymus was obviously loose and swollen, the arrangement of liver cell was disordered, and the bursa of fabricius formed vacuolated. Real-time PCR detection showed that the expression level of IRF7 gene and related immune genes in ALV-J group was significantly higher than that in control group (P < 0.05). To further study the role of chicken IRF7 during avian leukosis virus subgroup J (ALV-J) infection, we constructed an induced IRF7 overexpression and interfered chicken embryo fibroblasts (CEFs) cell and performed in vitro infection using low pathogenic ALV-J and virus analog poly(I:C). In ALV-J and poly(I:C) stimulated CEFs cells, the expression level of STAT1, IFN-α, IFN-β, TLR3 and TLR7 were increased after IRF7 overexpressed, while the results were just the opposite after IRF7 interfered, which indicating that IRF7 may be associated with Toll-like receptor signaling pathway and JAK-STAT signaling pathway. These findings suggest that chicken IRF7 is an important regulator of IFN and is involved in chicken anti-ALV-J innate immunity.

为了培育出抗病能力强的新禽类，首先要了解禽类抗病毒反应的机制。干扰素调节因子 7 (IRF7) 不仅是 I 型干扰素 (IFNs) 调节因子 (IRFs) 家族的成员，也是哺乳动物 IFN 反应的主要调节因子。然而，由于IRF3的缺失，家禽中IRF7是否参与宿主先天免疫反应仍不清楚。在这里，我们首先通过HE染色观察到随着ALV-J攻击时间的增加，胸腺明显松散肿胀，肝细胞排列紊乱，法氏囊形成空泡状。实时荧光定量 PCR 检测显示IRF7的表达水平ALV-J组基因及相关免疫基因显着高于对照组（P < 0.05）。为了进一步研究鸡IRF7在禽白血病病毒亚组 J (ALV-J) 感染中的作用，我们构建了诱导IRF7过表达并干扰鸡胚成纤维细胞 (CEFs) 细胞，并使用低致病性 ALV-J 和病毒类似物进行体外感染聚（I：C）。在ALV-J和poly(I:C)刺激的CEFs细胞中， IRF7过表达后STAT1、IFN-α、IFN-β、TLR3和TLR7的表达水平升高，而IRF7干扰后结果正好相反，即表明IRF7可能与Toll样受体信号通路和JAK-STAT信号通路有关。这些发现表明鸡IRF7是 IFN 的重要调节因子，并参与鸡抗 ALV-J 先天免疫。