Scientists created a working thymus, a vital immune system – “nerve centre” located near the heart, with connective tissue cells from a mouse embryo which were converted into a completely different cell strain by flipping a genetic “switch” in their DNA.
The resulting cells grew spontaneously into the whole organ when injected into the mouse with other similar cells.
Researchers from the MRC Centre for Regenerative Medicine at the University of Edinburgh, took cells called fibroblasts from a mouse embryo and converted them directly into a completely unrelated type of cell – specialised thymus cells – using a technique called ‘reprogramming’.
When mixed with other thymus cell types and transplanted into mice, these cells formed a replacement organ that had the same structure, complexity and function as a healthy native adult thymus.
The reprogrammed cells were also capable of producing T cells – a type of white blood cell important for fighting infection – in the lab.
The researchers hope that with further refinement their lab-made cells could form the basis of a readily available thymus transplant treatment for people with a weakened immune system. They may also enable the production of patient-matched T cells.