Stanford Medicine study flags unexpected cells in lung as suspected source of severe COVID

The lung-cell type that’s most susceptible to infection by SARS-CoV-2, the virus that causes COVID-19, is not the one previously assumed to be most vulnerable. What’s more, the virus enters this susceptible cell via an unexpected route. The medical consequences may be significant. Stanford Medicine investigators have implicated a type of immune cell known as an interstitial macrophage in the critical transition from a merely bothersome COVID-19 case to a potentially deadly one. Interstitial macrophages are situated deep in the lungs, ordinarily protecting that precious organby, among other things, engorging viruses, bacteria, fungi and dust particles that make their way down our airways. But it’s these very cells, the researchers have shown in a study published online April 10 in the Journal of Experimental Medicine, that of all known types of cells composing lung tissue are most susceptible to infection by SARS-CoV-2. SARS-CoV-2-infected interstitial macrophages, the scientists have learned, morph into virus...