Researchers from the Francis Crick Institute and the University College London have rebuilt a human thymus, an essential organ in the immune system, using human stem cells and a bioengineered scaffold.
The scientists rebuilt thymi using stem cells from patients who had to have the organ removed during surgery. When transplanted into mice, the bioengineered thymus was able to support the development of mature and functional human T lymphocytes in the immune system. This is the first-time scientists have successfully rebuilt a complete working thymus, a big step for further research into the treatment of severe immune deficiencies and developing new techniques for human organs.
To build the organ, researchers collected thymi from patients, they then grew thymic epithelial cells and thymic interstitial cells from the donated tissue into billions of cells. To obtain a scaffold of thymi, their removed all the cells from rat thymi, then repopulated it with up to 6 million of the thymic cells they had cultured. The cells grew onto the scaffolds and only after five day, the organs had developed to a similar stage as those seen in nine-week-old fetuses.