Investigating the role of ANP32A in the replication of Avian Influenza Virus

流感病毒感染家禽和猪等家畜，造成收入损失、社会和经济混乱。禽流感仍然是粮食安全的主要威胁之一。禽流感在动物宿主中的适应导致了在人类中传播的病毒，并具有引发紧急流感大流行的风险。我们已经研究了一系列宿主蛋白ANP32，它们被流感病毒增选来支持其复制。鸡和哺乳动物宿主的ANP32A之间的差异是保护猪和人免受禽流感病毒人畜共患感染的宿主范围障碍之一。禽流感病毒依赖于RNA的RNA聚合酶不能利用哺乳动物的ANP32A蛋白，除非它通过病毒PB2蛋白的突变来适应。我们先前已经证明，飞行鸟类中存在的ANP32A蛋白的形式与哺乳动物中的不同，这是因为存在额外的编码33个氨基酸的外显子，这些外显子有助于成熟蛋白质的形成。我们有初步数据表明，去除这个外显子可以减少禽流感病毒在鸡细胞中的复制。我们将确定病毒蛋白相互作用所需的ANP32A的特定区域。我们将使用我们开发的新的基因组编辑工具来修改鸡细胞，以测试我们的预测，即ANP32A的哪些定向变化将对禽流感病毒复制产生最显著的影响。我们将产生一系列ANP32A突变，并测试它们对禽流感聚合酶功能和病毒复制的影响。我们将确定含有修饰的ANP32A蛋白的编辑细胞的RNA转录组的任何全局变化。我们将研究ANP32A在基因组编辑动物中的功能。这些信息将为保护商业家禽免受AIV感染的控制战略提供参考。研究人类和牲畜中的流感病毒的研究人员也会对此感兴趣。

Influenza viruses infect domestic animals including poultry and pigs, causing loss of income, social and economic disruption. Avian influenza remains one of the major threats to food security. Adaptation of avian influenza in animal hosts leads to viruses that are transmitted in humans and carries the risk of driving emergent influenza pandemics. We have investigated a family of host proteins, ANP32, that are co-opted by influenza virus to support its replication. The difference between ANP32A in chickens and mammalian hosts accounts for one of the host range barriers that protect pigs and humans from zoonotic infections by avian influenza viruses. Avian influenza virus RNA-dependent RNA polymerase is unable to utilise the mammalian ANP32A protein unless it adapts by mutation of the viral PB2 protein. We have previously shown that the form of the protein ANP32A present in flighted birds differs from that in mammals due to presence of an additional exon encoding 33 amino acids that contribute to the mature protein. We have preliminary data suggesting that removal of this exon reduces or avian influenza virus replication in chicken cells. We will identify the specific regions of ANP32A needed for viral protein interactions. We will use new genome editing tools that we have developed to modify chicken cells to test our predictions of which targeted changes to ANP32A will have the most significant effect on avian influenza virus replication. We will generate a series of mutations of ANP32A and test their effects on avian influenza polymerase function and virus replication. We will determine any global changes in the RNA transcriptome of the edited cells containing modified ANP32A protein. We will investigate the function of ANP32A in genome edited animals. This information will inform control strategies for protection of commercial poultry from AIV infection. It will also be of interest to researchers studying influenza virus in humans and livestock.