A Look Inside Virus-Infected Cells

By Shlomo Maital

   Researchers at Israel’s Weizmann Institute have provided us with a revealing look inside cells infected with novel coronavirus. The research was led by Prof. Ido Amit, Dept. of Immunology, and reported in a front-page article in today’s Haaretz daily, by Ido Efrati.

       Amit is an expert in single-cell genomics, in which scientists analyze the DNA of single human cells. By analyzing single cells of severely ill patients with COVID-19, moderately ill ones and healthy persons, the scientists can map precisely how the insidious virus wreaks its havoc.

       Here is a short summary. The virus attacks epithelial cells in the lungs; these cells transport oxygen from the lungs to the blood, where it is distributed to the body’s vital organs.   This attack induces macrophages, a specialized cell that detects and (tries to) destroy the virus.   The Weizmann Institute scientists found that in seriously ill patients, the macrophages were replaced by monocytes, which are blood cells created by the body’s immune reaction. Ironically, an excess of those monocytes (as the body fights back against the virus) produces an overload of the immune reaction, known as a cytokine storm. This creates massive inflammation and actually hampers the immune system.

     The researchers, who have cooperated with other scholars in China and Italy, note that this cytokine storm occurs even before other signs appear.

     This suggests that a blood test could reveal which patients are high risk, even before their lungs show distress.   They also note that perhaps drugs or treatments can be developed to protect the lungs’ macrophages before the virus can seriously damage them.

     It is clear that those with unhealthy lungs, perhaps through smoking or other conditions, are more vulnerable.

       It is taking time, but thanks to cooperation among scientists worldwide, a clearer picture is beginning to emerge of precisely how the novel coronavirus makes us ill and kills some of us. This knowledge will ultimately lead to effective treatments.