A Link Discovered Between Stem Cells and Immunity

Cell Stem Cell, February 26, 2008

Researchers at Baylor College of Medicine in Houston, Duke University Medical School, and the National Institute of Allergy and Infectious Disease have collaborated in a study which resulted in the discovery of a link between immunology and stem cells. That link is a gene which is known as the interferon-inducible GTPase Lrg-47 gene. The study was led by Dr. Margaret Goodell, Professor of Pediatrics and Director of the Stem Cells and Regeneration Center at Baylor.

When mice who lacked this gene were infected with a bacteria that resembled tuberculosis, the natural stem cells of the mice did not respond by making new blood cells as a defense against the infection, as they normally would in healthy mice who have the missing gene, which has been known for the role that it plays in stress response. These results therefore suggest that the gene might also be involved in the production of normal blood cells, which would be needed whenever infection and disease threaten an organism.

This is the first study to indicate a direct link between immunology and stem cell activation, as mediated by a common gene. The interferon gamma proteins are well known as regulators of the immune system, and the discovery that this gene is also regulated by interferon gamma was somewhat of a surprise to the researchers, who also found that mice who are bred to lack this gene have abnormally low blood counts and easily die of infection. Additionally, the mice also were found to have stem cells which did not function well, especially when subjected to chemical or pathological stress. Even bone marrow transplants that were performed on the mice were unsuccessful.

Additional research will investigate further exactly how this gene controls stem cell activity, as well as the precise role that interferons play in the cell. The genetic, molecular and cellular mechanisms at work in these pathways have many applications to human health and disease.