Bik Promotes Cleavage of Viral Proteins to Enhance Influenza A Virus Infection

Bik 促进病毒蛋白裂解，增强甲型流感病毒感染

• 批准号: 8969925
• 负责人: Yohannes Afework Mebratu
• 金额: $ 27.25万
• 依托单位: LOVELACE BIOMEDICAL & ENVIRONMENTAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8969925
• 关键词: Address; Affect; Antiviral Agents; Apoptosis; Apoptotic; Appearance; Attenuated; BCL2 gene; Biology; Caspase; Caspase Inhibitor; Cell Death; Cells; Cessation of life; Cleaved cell; Country; Cytoplasm; Data; Development; Disease Progression; Electrical Resistance; Epidemic; Epithelial; Epithelial Cells; Evolution; Generations; Goals; HIV-1; Human; Infection; Influenza; Influenza A Virus, H1N1 Subtype; Influenza A virus; Intervention; Lead; Link; Lung Inflammation; Lung diseases; M2 protein; Mediating; Medical; Mitochondria; Molecular; Molecular Models; Mus; NP protein; Pathogenesis; Pathogenicity; Peptide Hydrolases; Play; Population; Predisposition; Protease Inhibitor; Protein Biosynthesis; Protein Family; Proteins; Recurrence; Reporting; Resistance; Review Literature; Role; Survival Analysis; Testing; Therapeutic Intervention; Vaccination; Vaccines; Viral; Viral Genome; Viral Proteins; Virus; Virus Diseases; Virus Replication; Weight; World War I; caspase-3; cellular targeting; cost; cytochrome c; design; effective intervention; effective therapy; flu; in vivo; influenza epidemic; influenzavirus; insight; intraperitoneal; knock-down; molecular modeling; mortality; mutant; novel; novel therapeutic intervention; pandemic disease; particle; pressure; pro-apoptotic protein; protein expression; public health relevance; respiratory; therapeutic target; viral RNA

 DESCRIPTION (provided by applicant): Influenza (flu) is a highly contagious respiratory disease that affects millions of people each year with significant cost to the economy. Currently, influenza A virus (IAV) of the subtype H1N1 is responsible for seasonal epidemics that may result in severe respiratory illness and deaths worldwide. The annual Influenza virus epidemics are estimated to cost the U.S. 10.4 billion in direct medical expenses and 16.4 billion in lost potential earnings. The frequent appearances of new strains of flu made the generation of effective vaccines difficult. Therefore, the detailed molecular mechanisms how IAV replicates and propagates need to be investigated to design effective antiviral drugs and vaccines. Influenza induces cell death in infected cells to facilitate virus replication. Our preliminary studies identified the Bcl-2 interacting killer (Bik) as a crucial cellular protein promoting IAV infection in human airway epithelial cells (AECs) and in mice. We found that IAV replication was attenuated in bik-/- compared to bik+/+ cells, as indicated by reduced viral titers. Following infection, bik-deficient mouse airway epithelial cells (MAECs) showed more stable trans-epithelial resistance following infection, were less sensitive to infection-induced cell death, and had reduced levels of viral RNA compared to bik-sufficient MAECs. Knockdown of Bik reduced viral protein expression levels and the sensitivity of human airway epithelial cells (HAECs) to IAV-induced cell death. Survival analysis of mice infected with IAV showed that bik-/- mice survived for significantly longer days after infection and were 10-fold less likely to die from infection compared to bik+/+ mice. Additionally, the bik+/+ mice lost significantly more weight compared to the bik-/- mice. IAV activated caspase 3 in a Bik-dependent manner and cleavage of viral NP and M2 proteins were inhibited when Bik was knocked down, implying that Bik-mediated caspase cleavage of viral proteins is linked to virus replication. Thus, we hypothesize that Bik is crucial for intracellular cleavage of components of viral protein(s) to promote virus replication. Although cleavage of viral proteins has been shown to promote virus infectivity, littl is known about relevant host cell proteases. This study will investigate the role of caspases in enhancing virus infectivity and tests whether targeted inhibition of caspases mitigate IAV infectivity. This hypothesis will be tested in Specific Aims 1 and 2. Aim 1 will investigate whethe Bik mediates caspase-dependent cleavage of viral proteins in IAV infected cells. Aim 2 will determine whether modulating the expression of Bik or inhibition of caspase activations mitigate viral replication and susceptibility to IAV- induced mortality in vivo. A better understanding of te molecular mechanisms how IAV manipulates host cellular proteins to facilitate virus replication will provide insight into new therapeutic approaches that target cellular and/or viral proteins to reduce infection and disease progression in humans.

 描述（由适用提供）：流感（流感）是一种高度传染性的呼吸道疾病，每年影响数百万的人，经济成本巨大。目前，亚型H1N1的影响病毒（IAV）导致季节性发作可能导致全世界严重的呼吸道疾病和死亡。据估计，年度流感病毒发作估计使美国直接医疗费用损失了14亿美元，潜在的收入损失了164亿。经常出现新的流感菌株，有效疫苗的产生困难。因此，详细的分子机制需要研究IAV如何复制和繁殖以设计有效的抗病毒药物和疫苗。流感诱导感染细胞中的细胞死亡，以促进病毒复制。我们的初步研究将Bcl-2相互作用杀手（BIK）确定为促进人类气道上皮细胞（AEC）和小鼠中IAV感染的至关重要的细胞蛋白。我们发现，与Bik+/+细胞相比，IAV复制在BIK - / - 中被衰减，如病毒滴度减少所示。感染后，缺乏BIK的小鼠气道上皮细胞（MAEC）在感染后显示出更稳定的跨上皮耐药性，对感染诱导的细胞死亡和 与自行型的MAEC相比，病毒RNA的水平降低。敲低BIK降低了病毒蛋白表达水平和人类气道上皮细胞（HAEC）对IAV诱导的细胞死亡的敏感性。感染IAV的小鼠的生存分析表明，与Bik+/+小鼠相比，感染后的Bik - / - 小鼠在感染后几天内生存更长的时间，而死亡的可能性降低了10倍。此外，与Bik - / - 小鼠相比，Bik+/+小鼠的重量明显更大。 IAV激活的caspase 3以BIK依赖性方式，当Bik被击倒时，抑制病毒NP和M2蛋白的裂解，这意味着病毒蛋白的BIK介导的caspase caspase裂解与病毒复制有关。这是我们假设BIK对于病毒蛋白的细胞内切割至关重要，以促进病毒复制。尽管已经证明了病毒蛋白的切割可以促进病毒感染，但对相关宿主细胞蛋白酶知之甚少。这项研究将研究胱天蛋白酶在增强病毒感染中的作用，并测试靶向抑制胱天蛋白酶是否减轻IAV感染。该假设将在特定的目标1和2中进行检验。目标1将研究BIK是否介导了IAV感染细胞中病毒蛋白的caspase依赖性裂解。 AIM 2将确定是否调节BIK的表达或抑制caspase激活的抑制，从而减轻病毒复制和对IAV诱导的体内死亡率的敏感性。对TE分子机制的更好理解是IAV如何操纵宿主细胞蛋白来促进病毒复制，将洞悉靶向细胞和/或病毒蛋白的新治疗方法，以减少人类的感染和疾病进展。