US researchers have developed the first lung organ-on-a-chip with a working immune system, a development that could significantly improve the ability to mimic the living organ and model disease. 

The technology was used to mimic the flu, an infection caused by influenza viruses, which affects nearly one billion people worldwide each year. Current influenza infection models are inadequate, costly and lack research tools, while existing lung organ-on-a-chip systems fail to replicate a functional immune system. 

Georgia Tech and Vanderbilt University researchers designed a chip that put together immune cells and small airway cells, which are crucial for lung immune defence and gas exchange, and blood vessel cell formation. By infecting the chip with influenza viruses, researchers observed tissue structure changes similar to those in severe flu patients. 

Crucially, these chips are capable of mimicking immune responses, such as immune cell recruitment and cytokine storm, an immune overreaction which occurs in influenza and other severe lung infections. 

“This device goes further than ever before in modelling human severe influenza and providing unprecedented insights into the complex lung immune response,” said Krish Roy, co-leader of the study published in Nature Biomedical Engineering. 

Although the organ-on-a-chip still lacks components of the full lung, the vision is to apply this technology in personalised medicine to predict therapy efficiency in different lung conditions.