State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, CAS, Wuhan, 430071, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Virol Sin. 2021 Oct;36(5):859-868. doi: 10.1007/s12250-021-00348-0. Epub 2021 Feb 9.
The COVID-19 pandemic, caused by the SARS-CoV-2 infection, is a global health crisis. While many patients have clinically recovered, little is known about long-term alterations in T cell responses of COVID-19 convalescents. In this study, T cell responses in peripheral blood mononuclear cells of a long-time COVID-19 clinically recovered (20-26 weeks) cohort (LCR) were measured via flow cytometry and ELISpot. The T cell responses of LCR were comparatively analyzed against an age and sex matched short-time clinically recovered (4-9 weeks) cohort (SCR) and a healthy donor cohort (HD). All volunteers were recruited from Wuhan Jinyintan Hospital, China. Phenotypic analysis showed that activation marker PD-1 expressing on CD4 T cells of LCR was still significantly lower than that of HD. Functional analysis indicated that frequencies of Tc2, Th2 and Th17 in LCR were comparable to those of HD, but Tc17 was higher than that of HD. In LCR, compared to the HD, there were fewer IFN-γ producing T cells but more IL-2 secreting T cells. In addition, the circulating Tfh cells in LCR were still slightly lower compared to HD, though the subsets composition had recovered. Remarkably, SARS-CoV-2 specific T cell responses in LCR were comparable to that of SCR. Collectively, T cell responses experienced long-term alterations in phenotype and functional potential of LCR cohort. However, after clinical recovery, SARS-CoV-2 specific T cell responses could be sustained at least for six months, which may be helpful in resisting re-infection.
由 SARS-CoV-2 感染引起的 COVID-19 大流行是一场全球卫生危机。虽然许多患者已经临床康复，但对于 COVID-19 康复者的 T 细胞反应的长期变化知之甚少。在这项研究中，通过流式细胞术和 ELISpot 测量了长时间 COVID-19 临床康复（20-26 周）队列（LCR）外周血单核细胞中的 T 细胞反应。将 LCR 的 T 细胞反应与年龄和性别匹配的短时间临床康复（4-9 周）队列（SCR）和健康供体队列（HD）进行比较分析。所有志愿者均来自中国武汉金银潭医院。表型分析表明，LCR 中 CD4 T 细胞上表达的激活标志物 PD-1 仍明显低于 HD。功能分析表明，LCR 中的 Tc2、Th2 和 Th17 频率与 HD 相当，但 Tc17 高于 HD。在 LCR 中，与 HD 相比，产生 IFN-γ的 T 细胞较少，但分泌 IL-2 的 T 细胞较多。此外，与 HD 相比，LCR 中的循环 Tfh 细胞仍然略低，尽管亚群组成已经恢复。值得注意的是，LCR 中的 SARS-CoV-2 特异性 T 细胞反应与 SCR 相当。总的来说，T 细胞反应在 LCR 队列的表型和功能潜力方面经历了长期的变化。然而，临床康复后，SARS-CoV-2 特异性 T 细胞反应至少可以持续六个月，这可能有助于抵抗再次感染。
