Objectives: High-magnitude CD8+ T cell responses are associated with mild COVID-19 disease; however, the underlying characteristics that define CD8+ T cell-mediated protection are not well understood. The antigenic breadth and the immunodominance hierarchies of epitope-specific CD8+ T cells remain largely unexplored and are essential for the development of next-generation broad-protective vaccines. This study identified a broad spectrum of conserved SARS-CoV-2 CD8+ T cell epitopes and defined their respective immunodominance and phenotypic profiles following SARS-CoV-2 infection. Methods: CD8+ T cells from 51 convalescent COVID-19 donors were analysed for their ability to recognise 133 predicted and previously described SARS-CoV-2-derived peptides restricted by 11 common HLA class I allotypes using heterotetramer combinatorial coding, which combined with phenotypic markers allowed in-depth ex vivo profiling of CD8+ T cell responses at quantitative and phenotypic levels. Results: A comprehensive panel of 49 mostly conserved SARS-CoV-2-specific CD8+ T cell epitopes, including five newly identified low-magnitude epitopes, was established. We confirmed the immunodominance of HLA-A*01:01/ORF1ab1637-1646 and B*07:02/N105-113 and identified B*35:01/N325-333 as a third epitope with immunodominant features. The magnitude of subdominant epitope responses, including A*03:01/N361-369 and A*02:01/S269-277, depended on the donors' HLA-I context. All epitopes expressed prevalent memory phenotypes, with the highest memory frequencies in severe COVID-19 donors. Conclusion: SARS-CoV-2 infection induces a predominant CD8+ T memory response directed against a broad spectrum of conserved SARS-CoV-2 epitopes, which likely contributes to long-term protection against severe disease. The observed immunodominance hierarchy emphasises the importance of T cell epitopes derived from nonspike proteins to the overall protective and cross-reactive immune response, which could aid future vaccine strategies.Keywords: CD8+ T cells; SARS‐CoV‐2; convalescence; epitopes; immunodominance; infection.

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乐备实（上海优宁维生物科技股份有限公司旗下全资子公司），是国内专注于提供高质量蛋白检测以及组学分析服务的实验服务专家，自2018年成立以来，乐备实不断寻求突破，公司的服务技术平台已扩展到单细胞测序、空间多组学、流式检测、超敏电化学发光、Luminex多因子检测、抗体芯片、PCR Array、ELISA、Elispot、PLA蛋白互作、多色免疫组化、DSP空间多组学等30多个，建立起了一套涵盖基因、蛋白、细胞以及组织水平实验的完整检测体系。

 
我们可提供从样本运输、储存管理、样本制备、样本检测到检测数据分析的全流程服务。凭借严格的实验室管理流程、标准化实验室操作、原始数据储存体系以及实验项目管理系统，已经为超过3000家客户单位提供服务，年检测样本超过100万，受到了广大客户的信任与支持。