Medical Research Council - London Institute of Medical Sciences

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Bitter Sugar Capsule

Sugary coat of hyaluronic acid helps bacteria evade immune cell response - potential treatment target

22 February 2023

Bitter Sugar Capsule

A spoonful of sugar helps the medicine go down, but a tiny capsule of sugar seems to help bacteria infect in the first place. Researchers studying Streptococcus pyogenes, which causes disease around the world, investigated how its sugar coating, made of hyaluronic acid, promotes severe infections. They discovered that when bacteria without the capsule infected mouse nose structures (pictured, red dots - particularly top left) and skin, they were more vulnerable to attack by the immune system. The capsule appeared to initially impede entry to the host cells, but ultimately help them evade the immune system. Unencapsulated bacteria infection was only effective if immune cells called neutrophils were absent or depleted, suggesting the capsule is key to dodging these cells in particular. Understanding the importance of neutrophils, and the role the hyaluronic acid capsule plays in helping bacteria dodge them, could steer the development of new approaches to treatment.

Written by Anthony Lewis

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