Immune systems use a previously unrecognized DNA detector to identify invading bacteria.

White blood cells called neutrophils recognize bacterial DNA, triggering a response that eventually kills the invaders. Zusen Fan and his colleagues at the Chinese Academy of Sciences Institute of Biophysics in Beijing found that a DNA-binding protein called Sox2 is also part of this bacterial surveillance system in mice and humans.

They discovered that Sox2 binds to bacterial DNA, and that bacterial infections were worse in mice that had been engineered to have no Sox2 expression in neutrophils. Infections were also worse in mice lacking another protein called TAB2, which interacts with Sox2. The findings could suggest new ways of treating infections, say the authors.

Nature Immunol. http://dx.doi.org/10.1038/ni.3117 (2015)