Scientists first reported in 2007 that a person’s cells could be reprogrammed to an embryo-like state, and so could form any type of cell in the body. Medical researchers immediately imagined using these ‘induced pluripotent stem (iPS) cells’ to create an endless supply of genetically matched replacement tissues to treat a range of diseases: fresh pancreatic tissue for diabetics, for example, or new nerve cells for people with Parkinson’s.
The strategy also seemed to offer a way around the ethical complexities of using stem cells derived from human embryos. But then came the worries about possible side effects…
The latest Nature study rejects that conclusion. Masumi Abe, a geneticist at the National Institute of Radiological Sciences in Chiba, Japan, and his team took iPS cells derived from mice and injected them back into the animals. For comparison, they injected other mice with embryonic stem (ES) cells. Yet unlike the 2011 study, which saw iPS cells perform worse than ES cells, the team found no differences between the immune responses of each group. The researchers also transplanted skin and bone-marrow cells derived from iPS or ES cells into mice and achieved similar success rates between the groups. The immune response of both sets of tissues is “indistinguishable”, says Abe.
Konrad Hochedlinger, a stem-cell scientist at Massachusetts General Hospital in Boston, says that the result will probably “calm people down” about iPS cells. “It is definitely reassuring,” he says.
The findings follow another positive study on iPS cells, published late last year, which found that the reprogramming process causes fewer mutations than previously thought...
As ethicist Wesley J.Smith comments, "Good ethics and good science have the cultural healing power to produce a common way forward. Onward."