Net Damage

Fishermen’s nets occasionally catch on nearby coral and do unintended damage to the ocean floor. Neutrophils are the body’s fishermen, immune cells casting nets to catch invasive microbes such as the COVID-19 virus. They release sticky webs made of DNA (blue in the web from a patient pictured) and proteins (green and red), called neutrophil extracellular traps (NETs). However these traps can also cause collateral damage, and may be causing lung problems associated with severe COVID-19 infections. To investigate, two studies searched for these NETs in samples from patients, and found them clustered in the lungs, clogging tiny airways and restricting blood flow. They even found that the virus can infect neutrophils and trigger excess NET production, causing the death of lung cells in lab tests. Treatments to prevent NET release negated the effects, however, suggesting this could help the ever-increasing number of patients in hospitals around the world.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image and research from work by Flavio Protasio Veras and colleagues, Ribeirão Preto Medical School, University of São Paulo, Brazil
• in Journal of Experimental Medicine, September 2020
• Image copyright held by the original authors
• and research by Coraline Radermecker and colleagues, Liege University, Liege, Belgium, in Journal of Experimental Medicine, September 2020