Analysis of Peripheral Blood T Cell Receptor and B Cell Receptor Repertoires Reveals Dynamic Adaptive Immune Responses in COVID-19 Patients

COVID-19 poses severe challenges to global public health. To understand T cell and B cell immune responses at the systemic level, we used next-generation sequencing to analyze T cell receptor (TCR) and B cell receptor (BCR) repertoires for patients at different COVID-19 disease stages. The adaptive immune response during early onset and recovery process in a patient was visualized in a panoramic manner. TCR repertoires had a dramatic reduction during the early onset of severe disease but recovered during the convalescent stage. Monitoring TCR repertoires could serve as an indicative biomarker to predict the disease progression. BCR repertoires had IgM to IgG isotype switching and a transient but dramatic IgA expansion. Dominant B cell clonal expansion with decreased diversity occurred after infection. This study demonstrated that immune repertoire analysis is a promising method for evaluating host immunity to a novel viral infection.