Severe acute respiratory syndrome coronavirus 2 infection: Role of interleukin-6 and the inflammatory cascade

Figure 1 The mechanism of the inflammatory storm. ① Antigen presenting; Dendritic cells activate T-cells by processing the antigen and delivering it to these cells; ② Start reproducing; Native T cells become activated by receiving antigens from dendritic cells; ③ A significant quantity of cytokines is secreted during the activation of T cells. These cytokines can activate B cells, macrophages, and NK cells; ④ Activated T cells also release cytokines and further activate macrophages, B cells and NK cells; ⑤ Cytokines secreted; These activated cells, in turn, lead to the secretion of inflammatory and pro-inflammatory cytokines; the resulting cytokine storm leads to the development of clinical signs of infection.

Figure 2 Interleukin-6 in the immune system. IL: Interleukin; JAK-STAT: Janus kinase and signal transducer and activator of transcription.