Tocilizumab: A Therapeutic Option for the Treatment of Cytokine Storm Syndrome in COVID-19

Abstract

Presently, we need more therapeutic molecules for this COVID-19 outbreak. The severity and mortality of the disease is associated with a high level of release of cytokine in the patients which is known as CRS (cytokine release syndrome) or cytokine storm syndrome. IL-6 is a type of pro-inflammatory cytokine which release in the severe COVID-19 patients. This cytokine initiates CRS the JAK-STAT or MAPK/NF-κB-IL-6 pathway. Tocilizumab, a humanized monoclonal antibody, is designed to bind both mIL-6R (membrane bound receptor for IL-6) and sIL-6R (soluble receptor for IL-6) and inhibit the JAK-STAT or MAPK/NF-κB-IL-6 signaling pathway. It finally stops the cytokine storm syndrome. However, we need to understand that how tocilizumab is bound with mIL-6R or sIL-6R. Similarly, we also need to understand more about the real molecular mechanism of activity of tocilizumab.

Keywords: COVID-19; Cytokine storm syndrome; Therapeutic option; Tocilizumab.

Figure 1

Probable mechanism of action of Tocilizumab, (A) Schematic diagram shows the cytokine storm by SARS-CoV-2 which can be blocked by Tocilizumab. (B) Molecular binding mechanism of Tocilizumab with two types of IL-6 receptor needs to know more.