The role of Bik in the replication and severity of influenza A virus

甲型流感病毒（IAV）是导致严重呼吸道疾病和死亡的季节性流行病的原因 全球范围内，仅在美国每年就花费数十亿美元。癌症患者的风险增加 流感后继发肺炎，可导致严重并发症。流感 由于缺乏有效的治疗干预措施， 新的病毒株，以及抗药性的迅速发展。控制感染的新方法可能 来源于细胞因子或途径，其直接或间接与病毒蛋白相互作用以增强或抑制 病毒复制IAV领域中的新兴概念之一是宿主细胞因子和途径是 这是维持IAV基因组完整性所必需的，这对病毒复制至关重要。我们的初步数据显示 宿主细胞蛋白Bik的缺乏与IAV复制的显著减少有关。我们 一项重要的发现发现是Bik缺乏会降低受感染气道中的病毒蛋白水平和病毒复制 上皮细胞此外，与bik +/+小鼠相比，bik-/-小鼠表现出较不严重的肺部炎症、减少的肺损伤和/或呼吸道感染。 病毒载量，并与IAV感染后的存活率显着增加。同样，一个核苷酸 增加Bik表达水平的BIK基因中的SNP（G → A）显著增加病毒NP 在原代正常人支气管上皮细胞（NHBE）中的水平和复制。此外，来自IAV的数据- 感染的人类队列显示BIK SNP的AA变体是与流感疾病相关的风险等位基因 严重性。Bik能破坏Bcl-2与IAV编码的核蛋白（NP）的相互作用，形成Bik/NP复合物 可能有助于病毒蛋白的组装。该提案的目标是确定宿主细胞蛋白Bik的作用， 促进病毒复制。我们的中心假设是IAV增加宿主细胞Bik蛋白的表达， 与Bcl-2/NP相互作用并破坏Bcl-2/NP相互作用以允许NP组装病毒核糖核蛋白的组分 （vRNP）并促进有效的病毒复制。为了验证这一假设，我们提出了两个具体目标。要求1 鉴定了IAV复制所需的病毒NP的Bik结合结构域。目标2确定是否 与Bik表达增加相关的BIK SNP是流感病毒疾病严重程度的危险因素， 人类研究旨在确定Bik/NP相互作用的位点，这些位点可能作为潜在的药物靶点 在未来这项研究可能会确定潜在的宿主遗传风险因素，有助于流感易感性 和严重程度，并可能对基于以下方面的针对性预防和治疗产生潜在影响： 易感因素 拟议的研究将通过剖析促进IAV的关键机制对该领域产生重大影响 复制的从长远来看，开发破坏Bik/NP相互作用的肽或小分子可能会改善 减少IAV复制。此外，这项研究将确定遗传因素有助于IAV疾病 严重性，这可能具有广泛的公共卫生意义。

Influenza A virus (IAV) is responsible for seasonal epidemics that results in severe respiratory illness and deaths worldwide, costing billions of dollars annually in the U.S. alone. Cancer patients are at increased risk of developing a secondary pneumonia after influenza, which can lead to significant complications. Influenza infections pose serious challenges due to the lack of effective therapeutic interventions, frequent appearances of new strains of the virus, and rapid development of drug resistance. New approaches to control infection may stem from cellular factors or pathways that directly or indirectly interact with viral proteins to enhance or inhibit virus replication. One of the emerging concepts in the field of IAV is that host cellular factors and pathways are required for maintaining IAV genome integrity, which is essential for viral replication. Our preliminary data show that a deficiency of a host cellular protein, Bik, is associated with significant reduction in IAV replication. Our major findings found that Bik deficiency reduces viral protein levels and viral replication in infected airway epithelial cells. Furthermore, bik-/- compared to bik+/+ mice exhibit less severe lung inflammation, reduced lung viral load, and a significant increase in survival rate after infection with IAV. Similarly, a single nucleotide polymorphism (SNP) in the BIK gene (G→A) that increases Bik expression levels significantly increases viral NP level and replication in primary normal human bronchial epithelial cells (NHBEs). Furthermore, data from an IAV- infected human cohort showed that the AA variant of BIK SNP is a risk allele associated with influenza disease severity. Bik disrupts the interaction of Bcl-2 with IAV-encoded nucleoprotein (NP) and form a Bik/NP complex that may help assemble viral proteins. The goals of this proposal are to define the role of a host cell protein Bik in promoting viral replication. Our central hypothesis is that IAV increases host cell Bik protein expression, which interacts with and disrupts Bcl-2/NP interaction to allow NP to assemble components of viral ribonucleoprotein (vRNP) and facilitate efficient viral replication. To test this hypothesis, we propose two Specific Aims. Aim 1 identifies the Bik-binding domain of viral NP required for IAV replication. Aim 2 determines whether a BIK SNP associated with increased Bik expression is a risk factor for influenza disease severity in humans. Studies are designed to identify the sites of Bik/NP interaction that may serve as potential drug targets in the future. This study may identify underlying host genetic risk factors contributing to influenza susceptibility and severity and may have potential implications in regard to targeted prevention and treatment based on susceptibility factors. The proposed studies will have significant impacts on the field by dissecting key mechanisms that promote IAV replication. In the long term, developing peptides or small molecules that disrupt Bik/NP interactions may improve therapy by reducing IAV replication. Further, this study will identify genetic factors contributing to IAV disease severity, which can have a broad public health significance.