Understanding evasion of cell intrinsic innate immunity in viral populations with high rates of replicative failure

细胞固有免疫是所有病毒病原体必须克服或以其他方式颠覆的障碍 才能成功地完成它们的感染生命周期。总的来说，这些路径探测非我或危险 相关分子，并作为反应，产生称为干扰素的信号蛋白，诱导局部 和全身性抗病原体反应。这些反应最终推动了对最严重的 感染，尽管它们也会导致许多观察到的病理。大多数，如果不是全部，病毒病原体编码 这些途径的拮抗剂；通常在干扰素产生的水平上。一种这样的病原体，人类 甲型流感病毒非常成功，只有大约0.5%的受感染细胞成功检测到病毒感染 早期时间点。尽管如此，这一小部分响应者对 疾病-干扰素途径有缺陷的人通常有极高的并发症或 感染包括流感在内的呼吸道病毒后死亡。 矛盾的是，虽然大多数病毒种群保持着对宿主检测的严格抑制，但他们 以相对较低的保真度复制。对于流感，只有大约10%的病毒颗粒可以成功完成 病毒的生命周期。其余的颗粒能够进入细胞，暴露出潜在的先天免疫 配体，但在某些步骤仍无法产生有感染性的后代。无论如何，绝大多数 病毒粒子，即使是那些不能完成病毒生命周期的病毒粒子，仍然没有被检测到。那么，是什么机制， 允许病毒群体保持不被宿主细胞检测到，尽管复制经常失败？ 作为这一雄心勃勃的调查路线的起点，我们将重点放在以下几个独立的机制上 我们已经拥有甲型流感病毒的初步数据，或有能力随时获得这种病毒 数据：1)甲型流感病毒片段基因组的结构如何影响潜在的范围 免疫刺激失败2)流感主要天然免疫拮抗剂的多功能性， NS1，影响病毒检测率，以及3)聚合酶错误率如何受制于先天免疫 压力。为了解决这些问题，我的团队将结合变异分析、深度突变 扫描，以及更经典的分子病毒学。通过描绘病毒种群必须克服的挑战 为了逃避先天免疫，以及它们做到这一点的机制，我们希望更好地向模型提供 病毒进化，甚至有可能确定利用这些挑战的新治疗路线。 病毒式 关键的是，我们的 方法已经确定了病毒生命周期中受监测的关键组成部分，以及 已经确定了具有理想特性的病毒变体作为潜在的候选疫苗或溶瘤 治疗学。

Cell intrinsic innate immunity is a barrier that all viral pathogens must overcome or otherwise subvert in order to successfully complete their infectious lifecycle. Collectively, these pathways detect non-self or danger associated molecules, and, in response, produce signaling proteins called interferons that induce both local and systemic anti-pathogen responses. These responses ultimately drive the clearance of most acute infections, although they also lead to much of the observed pathology. Most, if not all, viral pathogens encode antagonists of these pathways; frequently at the level of interferon production. One such pathogen, human influenza A virus, is so successful that only around 0.5% of infected cells successfully detect viral infection at early timepoints. Nevertheless, that small fraction of responders is crucial to the course of disease—individuals with defects in interferon pathways are often at extremely high risk of complications or death following infection by respiratory viruses, including influenza. Paradoxically, while most viral populations maintain stringent suppression of host detection, they replicate with relatively low fidelity. For influenza, only about 10% of viral particles can successfully complete the viral lifecycle. The rest of the particles are capable of entering cells and exposing potential innate immune ligands, but nevertheless fail at some step to produce infectious progeny. Regardless, the vast majority of virions, even those which cannot complete the viral lifecycle, still go undetected. What mechanisms, then, allow viral populations to remain undetected by host cells despite failing so frequently at replication? As a starting point to this ambitious line of inquiry, we are focusing on several discrete mechanisms in influenza A virus for which we already possess either preliminary data or the capacity to readily procure such data: 1) How the structure of the segmented genome of influenza A virus influences the range of potential immunostimulatory failure 2) How the multifunctionality of influenza’s predominant innate immune antagonist, NS1, influences rates of viral detection, and 3) How polymerase error rate may be subject to innate immune pressure. To address these questions my group will use a combination of variant analysis, deep mutational scanning, and more classical molecular virology. By profiling the challenges viral populations must overcome to evade innate immunity, and the mechanisms by which they do so, it is our hope to better inform models of viral evolution and potentially even identify novel therapeutic routes exploiting those challenges. viral Critically, our approaches have already identified key components of the viral lifecycle that are subject to surveillance, and have identified viral variants with desirable properties as potential vaccine candidates or oncolytic therapeutics.