Macrophage-epithelial communication promotes lung repair after injury

Lungs are continually exposed to infections and toxins from the air we breathe. These infections frequently damage the epithelium which is the internal lining of the lungs. With severe damage, the epithelium can die and compromise lung function, and widespread epithelial damage is frequently seen in fatal lung infections. It is therefore vital that the lung can repair itself promptly, but this process is very poorly understood.

After lung injury, it is known that cells called macrophages are important for repair. After eating dead cells and exposure to substances present during injury, the macrophages release small fluid-filled communication ‘packages’ called microvesicles. Simultaneously, macrophages release a protein called IGF-1 which instructs epithelial cells to take up microvesicles. Higher levels of IGF-1 and microvesicles are associated with improved survival in patients with lung injury but the mechanism behind this is not yet understood.

We intend to investigate this process with the aim of informing treatments for lung injury.