Hide and Sneak

When a virus enters a cell and starts taking over the machinery, an immune protein called major histocompatibility complex (MHC) class I goes into action. The complex collects pieces of viral proteins and displays them on the cell surface alerting other immune cells to the presence of the invader and directing the cells to attack. But some viruses are crafty and, by crippling the MHC class I pathway, can hide from the host immune system at least to some extent. Among these evasive viruses is SARS-CoV-2, which recent research shows turns off a key MHC class I-activating protein called NLRC5. An infected cell is shown here, coloured green, surrounded by uninfected cells that still express NLRC5 (reddish purple). Figuring out the mechanics of SARS-CoV-2’s immune evading tactics may inform the design of novel therapeutics that, if applied early during infection, could boost the host response and shorten the illness.

Written by Ruth Williams

Ruth Williams

Writer

Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

Website

• Image by Koichi Kobayashi, Hokkaido University Graduate School of Medicine, Sapporo, Japan
• and Texas A&M Health Science Center, Bryan, TX, USA
• Image copyright held by Koichi Kobayashi
• Research by Ji-Seung Yoo et al, published in Nature Communications, November 2021