A molecular brake on dendritic cell activation

A natural molecular brake in immune cells prevents autoimmune diabetes in mice, according to a report in Nature Medicine. These findings highlight one way in which the immune system prevents excessive activation and autoimmunity.

Dendritic cells are a type of immune cell that once activated, are critical for triggering an adaptive immune response. Most studies to date have focused on identifying factors that promote the maturation, activation and survival of dendritic cells.

Pamela Ohashi and her colleagues report that Nuclear Factor-kB1 (NF-kB1), a transcription factor that regulates inflammatory responses, is normally expressed in immature dendritic cells and holds them in a resting state. Dendritic cells lacking NF-kB1 become activated, release pro-inflammatory cytokines and stimulate T cell immune responses. In turn, these activated T cells attack pancreatic islets and cause autoimmune diabetes in mice.