New Technique Helps Immune System Detect, Fight Cancer.(Brief Article)

2001 NOV 21 - (NewsRx.com & NewsRx.net) -- A new therapeutic technique helps the immune system identify and attack abnormal cells, according to Howard M. Grey, MD, a leading expert in immunotherapy for cancer.

"It was once thought that tumors had some antigen that the immune system could recognize and handle, just as the immune system handles a bacterial or viral infection," according to Grey, president and scientific director of the La Jolla Institute of Allergy and Immunology, San Diego. "But that concept now appears incorrect for most tumors. Many tumors don't have any antigens that are unique or different from the antigens expressed by any other cell within the body. Therefore, the body does not recognize the cells as cancerous."

Grey spoke at the American Medical Association's 20th Annual Science Reporters Conference in San Francisco, California.

"While initial efforts with immunotherapy concentrated on developing antibodies that could recognize unique antigens on tumor cells, more recently it has become clear (through laboratory research with animals) that immune 'killer' cells are more effective in prevention and treatment of tumors," notes Grey. "These cells do not recognize intact tumor antigens as antibodies do, but rather small pieces of the antigens called peptides. These peptides are produced in the tumor itself as well as in special cells of the immune system called antigen presenting cells (APCs) that are critical to the induction of the active 'killer' white blood cells of the immune system."

One problem that has recently been recognized relates to differences in the machinery that generate the tumor antigen peptides in APCs and in the tumors themselves. These differences can result in the generation of different peptides in ...