Graydon Elizabeth K, Malloy Allison M W, Machmach Kawthar, Sun Peifang, Paquin-Proulx Dominic, Lizewski Stephen, Lizewski Rhonda, Weir Dawn L, Goforth Carl W, Anderson Stephen K, Letizia Andrew G, Mitre Edward
Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, USA.
Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
Curr Res Immunol. 2023 Jul 15;4:100064. doi: 10.1016/j.crimmu.2023.100064. eCollection 2023.
This study tested the hypothesis that high frequencies of natural killer (NK) cells are protective against symptomatic SARS-CoV-2 infection. Samples were utilized from the COVID-19 Health Action Response for Marines study, a prospective, observational study of SARS-CoV-2 infection in which participants were enrolled prior to infection and then serially monitored for development of symptomatic or asymptomatic infection. Frequencies and phenotypes of NK cells (CD3CD14CD19CD56) were assessed by flow cytometry. Individuals that developed asymptomatic infections were found to have higher pre-infection frequencies of total NK cells compared to symptomatic individuals (10.61% [SD 4.5] vs 8.33% [SD 4.6], p = 0.011). Circulating total NK cells decreased over the course of infection, reaching a nadir at 4 weeks, while immature NK cells increased, a finding confirmed by multidimensional reduction analysis. These results indicate that NK cells likely play a key role in controlling the severity of clinical illness in individuals infected with SARS-CoV-2.
自然杀伤（NK）细胞的高频率可预防有症状的SARS-CoV-2感染。样本取自海军陆战队COVID-19健康行动反应研究，这是一项关于SARS-CoV-2感染的前瞻性观察性研究，参与者在感染前入组，随后对有症状或无症状感染的发生进行连续监测。通过流式细胞术评估NK细胞（CD3CD14CD19CD56）的频率和表型。与有症状个体相比，发现发生无症状感染的个体在感染前的总NK细胞频率更高（10.61%[标准差4.5]对8.33%[标准差4.6]，p = 0.011）。在感染过程中，循环总NK细胞减少，在4周时降至最低点，而未成熟NK细胞增加，这一发现通过多维降维分析得到证实。这些结果表明，NK细胞可能在控制感染SARS-CoV-2个体的临床疾病严重程度方面发挥关键作用。
