SARS-CoV-2 Epitopes are Recognized by a Public and Diverse Repertoire of Human T-Cell Receptors

Abstract

Understanding the hallmarks of the adaptive immune response to SARS-CoV-2 is critical for fighting the COVID-19 pandemic. We assessed the antibody and T-cell reactivity in COVID-19 convalescent patients and healthy donors sampled both prior to and during the pandemic. The numbers of SARS-CoV-2-specific T cells were increased in healthy donors examined during COVID-19. Combined with the absence of symptoms and humoral response across that group, this finding suggests that some individuals might be protected by T-cell cross-reactivity. In convalescent patients we observed public and diverse T-cell response to SARS-CoV-2 epitopes, revealing T-cell receptor motifs with germline-encoded features. Bulk CD4+ and CD8+ T-cell responses to Spike glycoprotein were mediated by groups of homologous T-cell receptors, some of them shared across multiple donors. Overall, our results demonstrate that T-cell response to SARS-CoV-2, including the identified set of specific T-cell receptors, can serve as a useful biomarker for surveying viral exposure and immunity.Funding: Mikhail Shugay was supported by RFBR grant No 19-34-70011. Alexander Ivanov was supported by the Ministry of Science and Higher Education of the Russian Federation [Agreement No. 075-15-2019-1660]. Conflict of Interest: The authors declare no conflicts of interest.Ethical Approval: All donors signed the informed consent approved by the National Research Center for Hematology ethical committee before the enrollment. Additionally, 10 healthy hematopoietic stem cell donor samples and 10 healthy donor serum samples were obtained from the blood bank with the approval of the local ethical committee.