Adult human lung cells became expandable precursor-like cells

Researchers chemically reprogrammed adult human alveolar type 2 cells, which help maintain the lungs’ air sacs, in laboratory experiments. They isolated the cells from healthy donor lungs and grew them in a defined mixture of chemicals and growth factors. The cells multiplied through more than 30 generations of culture. With continued culture, they increasingly resembled precursor cells found in early lung development.

The cells organised into organoids, three-dimensional cell structures grown in the lab. Researchers then guided these structures to resemble mature lung air sacs. These mature-like organoids supported influenza A infection and mounted immune responses. Separately, researchers transplanted cells from precursor-like organoids into lung-injured mice. The cells remained in the lungs and developed into air-sac lining cells. Lung function improved in these mice.