Liu Yuchen, Zhu Wentao, Zhang Yanqi, Zhang Jingjing, Lv Maolin, Su Jianguo
Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, Shandong 266237, China.
Zool Res. 2024 Sep 18;45(5):972-982. doi: 10.24272/j.issn.2095-8137.2024.008.
Type IV interferon (IFN-υ) is a recently discovered cytokine crucial for host defense against viral infections. However, the role and mechanisms of IFN-υ in bacterial infections remain unexplored. This study investigated the antibacterial and antiviral functions and mechanisms of grass carp ( ) IFN-υ (CiIFN-υ) both and . The CiIFN-υ gene was first identified and characterized in grass carp. Subsequently, the immune expression of CiIFN-υ significantly increased following bacterial challenge, indicating its response to bacterial infections. The eukaryotic recombinant expression plasmid of CiIFN-υ was then constructed and transfected into fathead minnow (FHM) cells. Supernatants were collected and incubated with four bacterial strains, followed by plate spreading and colony counting. Results indicated that CiIFN-υ exhibited more potent antibacterial activity against gram-negative bacteria compared to gram-positive bacteria and aggregated gram-negative bacteria but not gram-positive bacteria. experiments further confirmed the antibacterial function, showing high survival rates, low tissue edema and damage, reduced tissue bacterial load, and elevated proinflammatory response at the early stages of bacterial infection. In addition, the antiviral function of CiIFN-υ was confirmed through and experiments, including crystal violet staining, survival rates, tissue viral burden, and RT-qPCR. This study highlights the antibacterial function and preliminary mechanism of IFN-υ, demonstrating that IFN-υ possesses dual functions against bacterial and viral infections.
IV型干扰素（IFN-υ）是最近发现的一种细胞因子，对宿主抵抗病毒感染至关重要。然而，IFN-υ在细菌感染中的作用和机制仍未得到探索。本研究调查了草鱼（ ）IFN-υ（CiIFN-υ）在体外和体内的抗菌和抗病毒功能及机制。CiIFN-υ基因首先在草鱼中被鉴定和表征。随后，细菌攻击后CiIFN-υ的免疫表达显著增加，表明其对细菌感染有反应。然后构建了CiIFN-υ的真核重组表达质粒并转染到黑头软口鲦（FHM）细胞中。收集上清液并与四种细菌菌株孵育，然后进行平板涂布和菌落计数。结果表明，与革兰氏阳性菌相比，CiIFN-υ对革兰氏阴性菌表现出更强的抗菌活性，并且能凝集革兰氏阴性菌但不能凝集革兰氏阳性菌。 实验进一步证实了其抗菌功能，显示在细菌感染早期存活率高、组织水肿和损伤低、组织细菌载量降低以及促炎反应增强。此外，通过 实验和 实验证实了CiIFN-υ的抗病毒功能，包括结晶紫染色、存活率、组织病毒载量和RT-qPCR。本研究突出了IFN-υ的抗菌功能和初步机制，表明IFN-υ对细菌和病毒感染具有双重功能。
