Hongbo Chi, PhD, Department of Immunology

    Waking up the body’s defense system

    Blood contains a large number of T cells, which act like soldiers that defend against infections and other invaders. When T cells detect a threat, they “wake up” and start multiplying into an army to destroy it. How T cells are triggered to multiply has been largely a mystery.

    St. Jude scientists have solved a central piece of the puzzle: T cells become fully awake thanks to the actions of a specific protein complex. Named mTORC1, this complex instructs T cells to start burning sugar and making lipids. These metabolic activities prompt the T cells to start multiplying into the army that fights an infection.

    “Our results answer a long-standing question about how one branch of the immune system is called into action at the first sign of an infectious disease,” said Hongbo Chi, PhD, of St. Jude Immunology. “Our data show that T cell metabolism could be targeted for therapeutic benefit in the treatment of asthma and other diseases.” The findings appear in the journal Immunity.

    December 16, 2013

    Read the news release