By Fiona Macdonald
Researchers from the University of Edinburgh in Scotland have taken a group of cells from a mouse embryo and grown them into a fully functional thymus, an immune system organ, in an adult mouse.
This is the first time a whole organ has been grown from scratch inside an animal, and the findings, which have been published in Nature Cell Biology, could pave the way for alternatives to organ transplants.
The thymus is an organ that’s found near the heart and produces T-cells, which fight infection and are critical to the immune system.
To grow the organ, the researchers first took fibroblast cells from a mouse embryo, genetically reprogrammed them and triggered their transformation into a type of cell that’s found in the thymus. To do this, they forced the fibroblast cells to express only a single gene, which isn’t normally expressed by fibroblasts. This gene lead to the production of a protein called FOXN1, which triggered the fibroblasts to turn into thymus cells.
These cells were then mixed with some support cells and placed inside mice, where they developed into a complete thymus.