Natural killer (NK) cells play an important role in innate immune responses to viral infections. Here, we review recent insights into the role of NK cells in viral infections, with particular emphasis on human studies. We first discuss NK cells in the context of acute viral infections, with flavivirus and influenza virus infections as examples. Questions related to activation of NK cells, homing to infected tissues and the role of tissue-resident NK cells in acute viral infections are also addressed. Next, we discuss NK cells in the context of chronic viral infections with hepatitis C virus and HIV-1. Also covered is the role of adaptive-like NK cell expansions as well as the appearance of CD56⁻ NK cells in the course of chronic infection. Specific emphasis is then placed in viral infections in patients with primary immunodeficiencies affecting NK cells. Not least, studies in this area have revealed an important role for NK cells in controlling several herpesvirus infections. Finally, we address new data with respect to the activation of NK cells and NK cell function in humans infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) giving rise to coronavirus disease 2019 (COVID-19).

自然杀伤 (NK) 细胞在病毒感染的先天免疫反应中发挥着重要作用。在这里，我们回顾了最近对 NK 细胞在病毒感染中的作用的见解，特别强调了人类研究。我们首先在急性病毒感染的背景下讨论 NK 细胞，以黄病毒和流感病毒感染为例。还讨论了与 NK 细胞激活、归巢到受感染组织以及组织驻留 NK 细胞在急性病毒感染中的作用相关的问题。接下来，我们在丙型肝炎病毒和 HIV-1 慢性病毒感染的背景下讨论 NK 细胞。还涵盖了适应性样 NK 细胞扩增的作用以及慢性感染过程中CD56 ^{- NK 细胞的出现。}然后特别强调影响 NK 细胞的原发性免疫缺陷患者的病毒感染。尤其重要的是，该领域的研究揭示了 NK 细胞在控制多种疱疹病毒感染中的重要作用。最后，我们讨论了有关感染严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 并导致 2019 年冠状病毒病 (COVID-19) 的人类 NK 细胞激活和 NK 细胞功能的新数据。