January 4, 2002
Study upends earlier thinking about immune cells' readiness against disease
More vigilant than minutemen, the immune system's T cells form one of the body's main lines of defense against infection and disease. A recent study by Dana-Farber Cancer Institute investigators is reversing scientists' understanding of how the cells are alerted to enemy invaders.
Vassiliki Boussiotis, MD, PhD, and her colleagues found that a signal from a gene called Tob keeps the cells in a dormant, or "quiescent," state. Only when that gene is shut off — when an infection is afoot — do the cells become activated against disease. The findings are published in the December 2001 issue of Nature Immunology.
"The quiescent state isn't something the cells lapse into, as had been previously thought, but one they must actively maintain," says Boussiotis, who is also an assistant professor of medicine at Harvard Medical School. The finding has direct implications both for the development of cancer vaccines and of safer techniques of organ transplantation.
Cancer vaccines seek to rouse the immune system to attack cancer cells. Organ transplantation, by contrast, involves "desensitizing" the immune system to foreign tissue so it doesn't launch a biochemical strike against donated organs. Knowing how to switch Tob on and off — thereby putting T cells either to sleep or on high alert — could lead to more potent vaccines and transplantation techniques that don't require patients to take as many anti-rejection drugs.
The research was supported by the National Institutes of Health.
Dana-Farber Cancer Institute (www.dana-farber.org) is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), a designated comprehensive cancer center by the National Cancer Institute.
