Researchers Use Adult Stem Cells to Replace Immune Systems in Mice

Bioethics   |   Steven Ertelt   |   Nov 23, 2007   |   9:00AM   |   WASHINGTON, DC

Researchers Use Adult Stem Cells to Replace Immune Systems in Mice Email this article
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by Steven Ertelt Editor
November 23,

Stanford, CA ( — Scientists at Stanford University in California have found another success story with the use of adult stem cells. Their studies of replacing the immune systems in mice come on the heels of a major announcement by scientists in Japan and Wisconsin that they were able to get adult stem cells to revert to their embryonic state.

In this new advance, the Stanford team said it found a method of transplanting blood-forming adult stem cells into the bone marrow of mice and replacing their failed immune systems.

Should scientists be able to replicate the studies in humans, it could provide a renewed hope for patients with autoimmune or genetic blood diseases.

Dr. Irving Weissman, one of the senior authors of the paper, published in the November 23 issue of the medical journal Science, said much work remains on getting the technique to work in humans, but he called the success in mice a small but significant step in helping patients.

The researchers don’t know whether the same molecule on human blood-forming stem cells would be the right one to target with a therapy. Also, the mice they used in the study lack a functioning immune system. They’ll need to get the therapy working in mice with a normal immune system before they can begin testing the technique in humans.

He said he thought the remaining issues in moving to work with humans could be overcome. Weissman said he considered this work to be the beginning of research that could lead to human studies.

"It is essentially a surgical strike against the blood-forming stem cells," Weissman said of the technique.

The method involves injecting the adult stem cells into the mice and the molecules attach to specific proteins that reside on the surface of blood-forming stem cells and destroy the cells.

The new blood-forming cells begin the process of repairing and replacing the immune system.

People with an autoimmune disease such as multiple sclerosis have immune systems in which immune cells attack the person’s own body. This technique could potentially fix the problem by giving patients a new system that wouldn’t attack the body.