Wednesday, May 04, 2011

'I'm a tumor and I'm over here!' Nanovaults used to prod immune system to fight cancer

UCLA scientists have discovered a way to "wake up" the immune system to fight cancer by delivering an immune system–stimulating protein in a nanoscale container called a vault directly into lung cancer tumors. The new method harnesses the body's natural defenses to fight disease growth.
The vaults, barrel-shaped nanoscale capsules found in the cytoplasm of all mammalian cells, were engineered to slowly release a protein — the chemokine CCL21 — into tumors. Pre-clinical studies in mice with lung cancer showed that the protein stimulated the immune system to recognize and attack cancer cells, potently inhibiting cancer growth, according to the study's co-senior author Leonard Rome, a researcher at UCLA's Jonsson Comprehensive Cancer Center and associate director of the California NanoSystems Institute (CNSI) at UCLA.
"Researchers have been working for many years to develop effective immune therapies to treat cancer, with limited success," said Rome, who has been studying vaults for decades. "In lung tumors, the immune system is down-regulated, and what we wanted to do was wake it up, find a way to have the cancer say to the immune system, 'Hey, I'm a tumor and I'm over here. Come get me.' "
The study appears in the May 3 issue of PLoS One, a peer-reviewed journal of the Public Library of Science.
Waking up the immune system
The new vault delivery system, which Rome characterized as "just a dream" three years ago, is based on a 10-year, ongoing research effort focused on using a patient's white blood cells to create dendritic cells, which are immune system cells that process antigen material and present it on their surface to other immune cells known as T cells, stimulating a response.