Though done in mice, the work establishes the principle of using unfertilized eggs as a source of customized embryonic stem cells that are genetically matched to the egg donor at the genes that control recognition of cells by the immune system, making them potentially useful for transplantation therapies. There are several caveats, including the fact that only females could benefit from this technique, donating their own eggs to generate the stem cells, and concerns that the tissues derived from this special type of embryonic stem cells might not function normally.
"This technique, if proven effective in humans, offers an efficient way of generating customized stem cell lines from women," says George Q. Daley, MD, PhD, senior author on the paper, who is the Associate Director of the Children's Hospital Boston Stem Cell Program and a member of the Executive Committee of the Harvard Stem Cell Institute. "It would eliminate tissue matching and tissue rejection problems, a major obstacle to successful tissue transplantation."
Embryonic stem cells are "master cells" that can generate all tissue types in the body. In 2002, Daley's laboratory collaborated with the laboratory of Rudolf Jaenisch, PhD, of the Whitehead Institute, MIT to demonstrate the first use of another method, somatic cell nuclear transfer, to create customized embryonic stem cells to repair genetic defects in mice. But somatic cell nuclear transfer (sometimes called therapeutic cloning) is a technically demanding and inefficient process that involves transferring the nucleus of a donor cell into an egg from which the nucleus has been removed.