On the Virtue of Restraint

Alexander Rudensky examines why an immune system capable of amplifying responses to pathogens also needs a dedicated mechanism of restraint. He connects the activity of effector CD4 T cells to the emergence of regulatory T cells and explores how loss of this regulatory population accounts for the severe disease associated with FOXP3 deficiency.

The lecture follows genetic experiments that test the continuing requirement for regulatory T cells and trace the stability of their lineage. It also considers regulatory T cells generated outside the thymus, their relationship with commensal microorganisms, and their role in limiting inflammation at mucosal barriers. Together these studies explain how a specialised cell lineage can maintain immune tolerance throughout life.