Previously unknown cell interaction is key in immune system attacks


Most of the time, the immune system is the body's protector, warding off invading viruses and bacteria before they can lead to infection and disease. But in autoimmune diseases, the immune system does an about face, turning on the body and attacking normal cells.

A major discovery by La Jolla Institute scientist Amnon Altman, Ph.D., and his colleagues, of a previously unknown molecular interaction that is essential for T lymphocyte activation, could have major implications for stopping this aberrantimmune system behavior and the accompanying undesirable immune responses that cause autoimmune diseases and allergies.

"Dr. Altman's finding is a breakthrough in our understanding of the complexbiochemical changes that trigger the immune system's T lymphocytes, which are disease-fighting white blood cells, to mount an immunological attack," said Mitchell Kronenberg, Ph.D., president & chief scientific officer of the La Jolla Institute, an international leader in immunology research. Dr. Kronenberg said the discovery opens the door to the potential development of new therapies for multiple sclerosis, rheumatoid arthritis and a host of other autoimmune diseases by blocking the cellular interaction identified by Dr. Altman, thereby shutting off the unwanted immune attack.

The findings were published online today in the journal Nature Immunology in a paper entitled "A motif in the V3 domain of the kinase PKC-θ determines its localization in the immunological synapse and functions in T cells via association with CD28." The immunological synapse refers to that region of the T cell (also called T lymphocyte) membrane, which contacts antigen-presenting cells to initiate an immune response, and where many of the early activation events take place. La Jolla Institute scientist Kok-Fai Kong, Ph.D., was first author on the paper and Dr. Altman was senior author. Scientists from Japan and Israel also collaborated on the study.