Viral respiratory infections are a common cause of severe disease, especially in infants, people who are immunocompromised, and in the elderly. Neutrophils, an important innate immune cell, infiltrate the lungs rapidly after an inflammatory insult. The most well-characterized effector mechanisms by which neutrophils contribute to host defense are largely extracellular and the involvement of neutrophils in protection from numerous bacterial and fungal infections is well established. However, the role of neutrophils in responses to viruses, which replicate intracellularly, has been less studied. It remains unclear whether and, by which underlying immunological mechanisms, neutrophils contribute to viral control or confer protection against an intracellular pathogen. Furthermore, neutrophils need to be tightly regulated to avoid bystander damage to host tissues. This is especially relevant in the lung where damage to delicate alveolar structures can compromise gas exchange with life-threatening consequences. It is inherently less clear how neutrophils can contribute to host immunity to viruses without causing immunopathology and/or exacerbating disease severity. In this review, we summarize and discuss the current understanding of how neutrophils in the lung direct immune responses to viruses, control viral replication and spread, and cause pathology during respiratory viral infections.

病毒性呼吸道感染是严重疾病的常见原因，特别是在婴儿、免疫功能低下的人和老年人中。中性粒细胞是一种重要的先天免疫细胞，在炎症损伤后迅速浸润肺部。中性粒细胞有助于宿主防御的最充分表征的效应机制主要是在细胞外，并且中性粒细胞参与保护免受多种细菌和真菌感染的作用已得到充分证实。然而，中性粒细胞在对细胞内复制的病毒的反应中的作用的研究较少。目前尚不清楚中性粒细胞是否有助于病毒控制或针对细胞内病原体提供保护，以及通过何种潜在免疫机制发挥作用。此外，需要严格调节中性粒细胞以避免旁观者对宿主组织造成损害。这在肺部尤其重要，脆弱的肺泡结构受损可能会损害气体交换，从而危及生命。本质上不太清楚中性粒细胞如何促进宿主对病毒的免疫力而不引起免疫病理学和/或加剧疾病的严重程度。在这篇综述中，我们总结并讨论了目前对肺部中性粒细胞如何指导对病毒的免疫反应、控制病毒复制和传播以及在呼吸道病毒感染期间引起病理的理解。