NEW YORK (Dispatches)-Scientists have transformed mature cells into primordial blood cells that regenerate themselves and the components of blood.
The work offers hope to people with leukaemia and other blood disorders who need bone-marrow transplants but can’t find a compatible donor. If the findings translate into the clinic, these patients could receive lab-grown versions of their own healthy cells.
One team, led by stem-cell biologist George Daley of Boston Children’s Hospital in Massachusetts, created human cells that act like blood stem cells, although they are not identical to those found in nature. A second team, led by stem-cell biologist Shahin Rafii of Weill Cornell Medical College in New York City, turned mature cells from mice into fully fledged blood stem cells.
Daley’s team chose skin cells and other cells taken from adults as their starting material. Using a standard method, they reprogrammed the cells into induced pluripotent stem (iPS) cells, which are capable of producing many other cell types. Until now, however, iPS cells have not been morphed into cells that create blood.
Then Daley and his colleagues inserted seven transcription factors—genes that control other genes—into the genomes of the iPS cells. Then they injected these modified human cells into mice to develop. Twelve weeks later, the iPS cells had transformed into progenitor cells capable of making the range of cells found in human blood, including immune cells. The progenitor cells are "tantalizingly close” to naturally occurring ‘haemopoetic’ blood stem cells, says Daley.