One of the keys to good health is maintaining a delicate balance between the life and death of cells. Researchers know that glitches in the mechanism that kills off certain immune-system cells can lead to serious "autoimmune" diseases--with the immune-system cells running amok and attacking the wrong targets. Now, scientists are beginning to understand why that happens.
In research reported in the Mar. 25 issue of Science, scientists at the University of Alabama and LXR Biotechnology Inc. in Richmond, Calif., discovered that victims of systemic lupus erythematosus, an autoimmune disorder, have abnormal amounts of a short version of a protein called Fas. Normally, Fas proteins attach to cell membranes and play a role in causing cell death. But the short versions lack the membrane-binding section, so they float around in the bloodstream, preventing the normal "death" signal from reaching the cells. Healthy mice injected with the short Fas protein quickly develop an autoimmune disease. The scientists therefore suggest that extracting this protein from the blood of patients might offer a simple, effective treatment.