RT Journal Article SR Electronic T1 Longitudinal high-throughput TCR repertoire profiling reveals the dynamics of T cell memory formation after mild COVID-19 infection JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.05.18.100545 DO 10.1101/2020.05.18.100545 A1 Minervina, Anastasia A. A1 Komech, Ekaterina A. A1 Titov, Aleksei A1 Koraichi, Meriem Bensouda A1 Rosati, Elisa A1 Mamedov, Ilgar Z. A1 Franke, Andre A1 Efimov, Grigory A. A1 Chudakov, Dmitriy M. A1 Mora, Thierry A1 Walczak, Aleksandra M. A1 Lebedev, Yuri B. A1 Pogorelyy, Mikhail V. YR 2020 UL http://biorxiv.org/content/early/2020/05/18/2020.05.18.100545.abstract AB COVID-19 is a global pandemic caused by the SARS-CoV-2 coronavirus. T cell response is a critical part of both individual and herd immunity to SARS-CoV-2 and the efficacy of developed vaccines. However neither the dynamics and cross-reactivity of the SARS-CoV-2-specific T cell response nor the diversity of resulting immune memory are well understood. In this study we use longitudinal high-throughput T cell receptor sequencing to track changes in the T cell repertoire following two mild cases of COVID-19 infection. In both donors we identified SARS-CoV-2-responding CD4+ and CD8+ T cell clones. We describe characteristic motifs in TCR sequences of COVID-19-reactive clones, suggesting the existence of immunodominant epitopes. We show that in both donors the majority of infection-reactive clonotypes acquire memory phenotypes. Certain CD4+ clones were detected in the memory fraction at the pre-infection timepoint, suggesting participation of pre-existing cross-reactive memory T cells in the immune response to SARS-CoV-2.Competing Interest StatementThe authors have declared no competing interest.