Scientists from Yale University (USA) have identified the mechanism of immune response formation that leads to a severe course of COVID-19. The findings of the new study are published in the journal Nature.

Previously, scientists found that the SARS-CoV-2 virus, by entering the lungs, can trigger a cytokine storm, which is a hyperactive immune response that leads to severe inflammation in the lungs up to and including death.

In the study, scientists found that immune cells, not just the epithelial cells covering the lungs, can harbor the virus. During identification of the pathogen, inflammasomes begin releasing cytokines that provoke an attack by their congeners in an attempt to interrupt the infection. In doing so, the cytokines concentrate inflammatory cells from the blood into the lungs, leading to the development of pneumonia.

Based on their findings, the researchers treated infected laboratory mice for viral lung inflammation by blocking the specific NLPR3 protein responsible for inflammation.

After this treatment, the test subjects continued to have infected immune systems, but these cells were no longer inflamed and therefore could not contribute to serious damage to the body. NLPR3 blockade, when combined with antiviral therapy, could provide a new way to treat COVID-19-induced pneumonia as well as prevent severe cases of coronavirus infection.