Understanding the hallmarks of the immune response to SARS-CoV-2 is critical for fighting the COVID-19 pandemic. We assessed antibody and T cell reactivity in convalescent COVID-19 patients and healthy donors sampled both prior to and during the pandemic. Healthy donors examined during the pandemic exhibited increased numbers of SARS-CoV-2-specific T cells, but no humoral response. Their probable exposure to the virus resulted in either asymptomatic infection without antibody secretion or activation of preexisting immunity. In convalescent patients, we observed a public and diverse T cell response to SARS-CoV-2 epitopes, revealing T cell receptor (TCR) motifs with germline-encoded features. Bulk CD4⁺ and CD8⁺ T cell responses to the spike protein were mediated by groups of homologous TCRs, some of them shared across multiple donors. Overall, our results demonstrate that the T cell response to SARS-CoV-2, including the identified set of TCRs, can serve as a useful biomarker for surveying antiviral immunity.

了解对抗SARS-CoV-2的免疫反应的标志对于对抗COVID-19大流行至关重要。我们评估了大流行之前和期间采集的恢复性COVID-19患者和健康供体的抗体和T细胞反应性。在大流行期间检查的健康供体显示出SARS-CoV-2特异性T细胞数量增加，但没有体液反应。他们可能接触病毒会导致无症状感染而无抗体分泌或激活已有的免疫力。在恢复期患者中，我们观察到对SARS-CoV-2表位的公开且多样的T细胞反应，揭示了具有种系编码特征的T细胞受体（TCR）图案。批量CD4 ⁺和CD8 ⁺T细胞对刺突蛋白的反应是由同源TCR组介导的，其中一些在多个供体之间共享。总体而言，我们的结果表明，对SARS-CoV-2的T细胞反应（包括已鉴定的TCR集）可以用作调查抗病毒免疫力的有用生物标记。