ABOVE: An artist’s rendering of the SARS-CoV-2 virus
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The coronavirus known as SARS-CoV-2, the causative agent of the COVID-19 pandemic, induces a puny innate immune response compared other respiratory viruses such as the flu. In a preprint posted on bioRxiv on May 12, researchers have shown in cell culture that a viral protein called open reading frame 3b (ORF3b) actively blocks the induction of type I interferon, a crucial aspect of that response.
This protein “is clearly a very good blocker of these early innate defenses of the cells, and it relates perfectly to what we see in organoids and animal models and in COVID-19 patients,” says Benjamin tenOever, a virologist at the Icahn School of Medicine at Mount Sinai in New York. “The virus—for reasons like ORF3b—is very good at shutting off and minimizing the amount of this key antiviral defense called interferon, which plays a really ...