To: Montana Wildhack who wrote (6495 ) 1/18/2001 11:40:43 PM From: DaveAu Read Replies (1) | Respond to of 14101 Wolf, I thought the stock went down today because you and the Chief sold. After all, they've cured Arthritis again - I read it in the National Post:nationalpost.com Researchers claim 'Holy Grail' Prolific Toronto team tags a protein as the off switch of the immune system Tom Arnold National Post A team of Canadian scientists has discovered the "Holy Grail" of the signalling process the human body uses to control its immune system, a finding that could one day halt the development of cancer, diabetes, arthritis and heart disease. Researchers have discovered that the protein CD45 contains a master switch capable of turning off hormones and proteins in the immune system. The switch could help shut down growth of diseases, stave off viral infections and prevent rejection of transplanted organs. "It is the Holy Grail of the body's cellular signalling system," said lead researcher Dr. Josef Penninger, an immunologist at the Amgen Institute and the Ontario Cancer Institute, a research centre at Princess Margaret Hospital in Toronto. "Our cells rely on the delicate balance of communications signals to grow normally and produce blood cells. However, when a signal cannot be stopped, the cells overgrow and we run into trouble. We have discovered that it is CD45 that sends the 'ceasefire' signal to cells." Dr. Penninger called the finding one of his most important discoveries. "People understand very much how you turn on a cell but people have had not much idea about how the master off switch works. Everyone was looking for it. Finding this out is kind of like the ultimate prize in this field." The research is published in today's issue of Nature, an international journal. It is Dr. Penninger's 126th scientific finding to be published. It marks the sixth major discovery to emerge from the same Canadian lab in less than two years. Dr. Penninger's recent research has attracted headlines around the world. "It's an important step in that it identifies a new function for CD45," concluded Dr. John Cambier, chairman of the department of immunology at the University of Colorado Health Sciences Center and the National Jewish Medical and Research Center in Denver. He is considered an international expert on CD45. "I'm not sure that I would consider it the Holy Grail of understanding regulation of cell growth. But nonetheless the observations are very important because they do illustrate a new function in regulation of growth." The human body contains tens of thousands of CD45, a protein that sits on the surface of red and white blood cells. First discovered 13 years ago, it was believed the protein played a limited role with two different types of cells. "We set out to find additional function of CD45 just based on the idea that there must be something else," Dr. Penninger said of his 13-member team. "In 1993 somebody told me that we know all about CD45 and we will never find anything new about it," Dr. Penninger said. The researchers genetically engineered mice that could not make the protein so they could compare how these mice and normal mice fared against a virus. "If there's a virus infection, our lymph nodes are swelling up but when the virus is killed the system must be shut down," said Dr. Penninger. "For some people it doesn't. And if you cannot stop the system, what we get is tumours because the cells overgrow, or auto-immune diseases like diabetes or multiple sclerosis because our cells cannot stop attacking." Scientists will now look to develop a drug capable of switching off the protein, he said. For instance, since most cancers require particular cells to grow, he said, a new drug that will interfere with the protein and turn off CD45 could halt the proliferation of cancerous cells. Dr. Arthur Weiss, an immunologist at the University of California in San Francisco, called the discovery "interesting and provocative. I've heard rumours about it. It is an unexpected and interesting finding." Dr. Penninger has emerged as a leader in Canada's research community. He came to Toronto from Austria in 1990 to work with Dr. Tak Mak, a well-known immunologist. By 1993, he had his own lab. Last year, he discovered the molecule that regulates movement of white blood cells, a major finding that could one day lessen the likelihood of heart attack, stroke and dying from the flesh-eating disease. His lab also solved the genetic mystery of how a common, contagious cold virus carried by 70% of the human population triggers heart disease. The findings will help predict who is at serious risk of cardiovascular disease and how it can be prevented. Dave