Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Cell Mol Immunol. 2021 Oct;18(10):2325-2333. doi: 10.1038/s41423-021-00750-4. Epub 2021 Aug 19.
In addition to CD4 T cells and neutralizing antibodies, CD8 T cells contribute to protective immune responses against SARS-CoV-2 in patients with coronavirus disease 2019 (COVID-19), an ongoing pandemic disease. In patients with COVID-19, CD8 T cells exhibiting activated phenotypes are commonly observed, although the absolute number of CD8 T cells is decreased. In addition, several studies have reported an upregulation of inhibitory immune checkpoint receptors, such as PD-1, and the expression of exhaustion-associated gene signatures in CD8 T cells from patients with COVID-19. However, whether CD8 T cells are truly exhausted during COVID-19 has been a controversial issue. In the present review, we summarize the current understanding of CD8 T-cell exhaustion and describe the available knowledge on the phenotypes and functions of CD8 T cells in the context of activation and exhaustion. We also summarize recent reports regarding phenotypical and functional analyses of SARS-CoV-2-specific CD8 T cells and discuss long-term SARS-CoV-2-specific CD8 T-cell memory.
除了 CD4 T 细胞和中和抗体，CD8 T 细胞也有助于患有 2019 年冠状病毒病（COVID-19）的患者对 SARS-CoV-2 的保护性免疫反应，COVID-19 是一种持续流行的疾病。在 COVID-19 患者中，常见到表现出激活表型的 CD8 T 细胞，尽管 CD8 T 细胞的绝对数量减少。此外，几项研究报告称，COVID-19 患者的 CD8 T 细胞中，抑制性免疫检查点受体（如 PD-1）上调，以及衰竭相关基因特征的表达。然而，CD8 T 细胞在 COVID-19 期间是否确实衰竭一直是一个有争议的问题。在本综述中，我们总结了对 CD8 T 细胞衰竭的现有认识，并描述了在激活和衰竭背景下 CD8 T 细胞表型和功能的现有知识。我们还总结了最近关于 SARS-CoV-2 特异性 CD8 T 细胞的表型和功能分析的报告，并讨论了 SARS-CoV-2 特异性 CD8 T 细胞的长期记忆。
