Scientists have uncovered how lung tissues avoid excessive damage in response to airborne irritants and infections. The findings reveal important insights into the possible treatment of patients with complications triggered by respiratory infections.
Lungs are delicate tissues that are constantly exposed to multiple inhaled microbes and microscopic particles. Excessive inflammation leads to scarring, which could interfere with lung gas-exchange function.
Online in Nature Immunology, Tracy Hussell and colleagues report that a molecule called CD200R exerts a dampening effect on specific immune cells residing in the lung. CD200R acts to increase the threshold required to activate an immune response in the lungs. Once such a response is initiated, CD200R reduces lung inflammation, lessening damage to lung tissues. Mice lacking CD200R had a lower survival rate in response to influenza infection, despite maintaining the ability to control this virus. Death was due to excessive collateral tissue damage brought about by the unrestrained immune cells.
Tracy Hussell (Imperial College London, UK)
Abstract available online.
(C) Nature Immunology press release.
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