Induced Pluripotent Stem Cell Treatment Suffers a Setback

May 19, 2011   

In a study published in Nature, researchers report that tissues made from induced pluripotent stem cells, or iPS cells, might be rejected by a patients immune system, even when the tissue is transplanted into the same person from which the cells were made. Induced pluripotent stem cells are adult stem cells that have been genetically reprogrammed to have the pluriopotency character of embryonic stem cells. This means the iPS cells can theoretically be reprogrammed to grow into different types of tissue, such as nerve, heart, liver, or other types of tissue.

When initially invented in 2007, iPS cells held promise for the regenerative medicine field because they held advantages over embryonic stem cells and other adult stem cells. The two major advantages over embryonic stems cells were that these cells were not controversial because they were adult stem cells and did not require the destruction of human embryos and it was assumed that the tissues created from the patients own iPS cells would not be rejected by that patients immune system. The pluripotency character of these cells created the advantage over other adult stem cells. This study has finally tested the latter assumption.

The study was led by Yang Xu, a molecular biologist at the University of California, San Diego. When Xus team transplanted the iPS cells into genetically identical mice, the iPS cells made from mouse skin cells were rejected by the immune systems of those mice. It is not clear if the same results would hold true in humans, but other scientists assume they would.

Although this study may create a setback for regenerative medicine, iPS cells are still a valuable research tool. Many scientists are using iPS cells to create cells (for example, nerve cells from someone with Parkinsons disease) that can be used to study diseases and treatments in the laboratory.

Fuerst Ittleman recognizes the promise that stem cells hold for regenerative medicine. We will continue to monitor future studies with iPS cells and other stem cells. For more information the regulatory oversight of stem cells, contact us at