Mucosal immune responses against viruses are orchestrated by myeloid cells such as macrophages, conventional DCs, plasmacytoid DCs, and monocyte-derived DCs . Accumulating evidence suggests that deregulation of myeloid cell-mediated responses potentially triggers lymphopenia, cytokine release syndrome, acute respiratory distress syndrome , and pathogenic inflammation with high level secretion of IL-6, IL-2, IL-7, IFN-ɣ, IFN-I, and type III IFNs 81 in COVID-19 patients with severe clinical manifestations.