Preventing cells from committing suicide.

Every day, for reasons that are not understood clearly, certain human cells commit suicide. Some, such as those that have been infected by a virus, kill themselves to preserve the health of the body as a whole. Others self-destruct simply because they sense that a threat to their survival or merely something unfamiliar is lurking nearby.

This process, called apoptosis or programmed cell death, is a normal biological occurrence that can promote proper organ development and help to prevent cancer. Nevertheless, it is unwelcome in modern biotech labs, where scientists turn living cells into miniature pharmaceutical factories that produce proteins, enzymes, antibodies, and viruses to help patients with an array of illnesses. Apoptosis prompts many of these microscopic workers to put physiological "guns to their heads" after just a few days on the job. Working closely with molecular biologists, Michael J. Betenbaugh, an associate professor in the Department of Chemical Engineering, Johns Hopkins University, Baltimore, Md., is trying to disable these guns and allow the drug-making cells to lead Ionger, more productive lives.

If scientists can find a way to stop cellular suicide, they may be able to keep some cardiac cells from killing themselves after a heart attack. They also may be able to extend the life of artificial organs made from animal tissue. The key is to halt apoptosis, which often is triggered by changes in a cell's environment. "It may be a viral infection, the loss of a key nutrient, radiation, or a chemical toxin--all at sublethal levels," Betenbaugh explains. "These would not kill the cell by themselves. Nevertheless, the...