Researchers at the Stanford University School of Medicine found a way to transplant new blood-forming stem cells into the bone marrow of mice, which could become an effective way to treat autoimmune diseases.
The problem with transplanting new stem cells into the marrow is that the old ones first must be removed, which is currently done by intensive chemotherapy or radiation. Those processes eliminate the cells of the bone marrow but also damage other tissue and can cause lasting effects including infertility, brain damage, and an increased risk of cancer.
One way around this problem would be to find a way to eliminate only the blood-forming stem cells without affecting bone marrow cells or other tissues. The investigators accomplish that feat by injecting the mice with ACK2, an antibody that blocks c-kit function. This technique eliminated the blood-forming stem cells without otherwise harming the mice. When the researchers transplanted new blood-forming stem cells into the mice, those cells took up residence in the bone marrow and established a new blood and immune system.
Many aspects of the technique would need to be adapted before it can be tested in humans, caution the scientists. First, 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. Still, the investigators believe the remaining hurdles could eventually be overcome.
The study is published in the November 23 issue of Science.