X-Message-Number: 11287 Date: Thu, 18 Feb 1999 19:28:08 -0500 From: Jan Coetzee <> Subject: Protein Holds Clues About Aging Cancer Fighting Protein Holds Clues About Aging LONDON (Reuters) - A protein that helps the body fight cancer may hold important clues about the aging process. New Scientist magazine said U.S. scientists suspect tumor necrosis factor (TNF), a protein that triggers apoptosis, or programmed death, in diseased or mutated cells, also weakens the immune system as people grow older. ``Researchers in California say that as the body ages, protective cells of the immune system become hypersensitive to the protein, and die at high rates,'' the weekly magazines said Wednesday. Immunologist Sudhir Gupta, and a team of researchers at the University of California at Irvine, examined levels of CD4 and CD8 immune cells in blood samples taken from students and retired professors. ``When exposed to TNF, 26 percent of the CD8 cells from the young subjects underwent apoptosis. By contrast, 40 percent of the aged CD8s committed suicide. The researchers found a similar increase in cell death among the older group's CD4 cells, suggesting they had become more sensitive to TNF,'' the magazine added. Gupta said TNF is only part of the story of the weakening immune system and aging, but it could be an important one. He believes drugs could one day help to slow the process. ``If we can delay the cell-death process, we may improve not just life span but the quality of life in old age,'' he said. J.C. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11287