Single-cell multi-omics analysis of the immune response in COVID-19

The single-cell transcriptome and surface proteome dataset was obtained from peripheral blood mononuclear cells (PBMCs) of COVID-19 patients with asymptomatic, mild, moderate, severe and critical diseases. An expansion of specific monocyte population expressing gene transcripts involving in platelet activation was observed, which interacted with platelet (predicted to be monocyte-platelet aggregation), and these cells were suggested to be involving in the replenishment of alveolar macrophage pool. Hematopoietic stem cells in peripheral blood were primed toward megakaryopoiesis, resulting in the increased platelets. Clonally expansion of CD8+ T cells was a characteristic of severe disease, whereas circulating follicular helper T cells, which may support the efficient antibody production from B cells, were remarkable in mild disease. The relative loss of IgA2 was observed in symptomatic disease despite of the expansion of plasma B cells.