press_release_conclusion: Research findings published today (April 29) in the journal Science by Dr David Sansom and his team in the MRC Centre for Immune Regulation at Birmingham show how a protein, called CTLA-4, keeps the immune system damped down during day-to-day activities and prevents inappropriate aggressive behaviour from T cells, the 'command centre of our immune response'.
abstract_conclusion: These data reveal a mechanism of immune regulation in which CTLA-4 acts as an effector molecule to inhibit CD28 costimulation by the cell-extrinsic depletion of ligands, accounting for many of the known features of the CD28-CTLA-4 system.