Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China.
Center for Human Disease Immuno-monitoring, Beijing Friendship Hospital, Beijing, China.
Front Immunol. 2021 Feb 2;12:603563. doi: 10.3389/fimmu.2021.603563. eCollection 2021.
The high infection rate and rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) make it a world-wide pandemic. Individuals infected by the virus exhibited different degrees of symptoms, and most convalescent individuals have been shown to develop both cellular and humoral immune responses. However, virus-specific adaptive immune responses in severe patients during acute phase have not been thoroughly studied. Here, we found that in a group of COVID-19 patients with acute respiratory distress syndrome (ARDS) during hospitalization, most of them mounted SARS-CoV-2-specific antibody responses, including neutralizing antibodies. However, compared to healthy controls, the percentages and absolute numbers of both NK cells and CD8 T cells were significantly reduced, with decreased IFNγ expression in CD4 T cells in peripheral blood from severe patients. Most notably, their peripheral blood lymphocytes failed in producing IFNγ against viral proteins. Thus, severe COVID-19 patients at acute infection stage developed SARS-CoV-2-specific antibody responses but were impaired in cellular immunity, which emphasizes on the role of cellular immunity in COVID-19.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的高感染率和快速传播使其成为全球性大流行。受该病毒感染的个体表现出不同程度的症状，大多数康复个体已被证明产生了细胞和体液免疫反应。然而，严重患者在急性期的病毒特异性适应性免疫反应尚未得到彻底研究。在这里，我们发现，在一组住院期间患有急性呼吸窘迫综合征（ARDS）的 COVID-19 患者中，大多数患者都产生了 SARS-CoV-2 特异性抗体反应，包括中和抗体。然而，与健康对照组相比，严重患者外周血中的 NK 细胞和 CD8 T 细胞的百分比和绝对数量明显减少，CD4 T 细胞中的 IFNγ表达降低。最值得注意的是，他们的外周血淋巴细胞未能针对病毒蛋白产生 IFNγ。因此，急性感染期的重症 COVID-19 患者产生了 SARS-CoV-2 特异性抗体反应，但细胞免疫受损，这强调了细胞免疫在 COVID-19 中的作用。
