As a first line of defence against microbes, immune cells called neutrophils release webs of uncoiled DNA strands and antimicrobial molecules to ensnare and kill the invaders (pictured). Researchers have identified two enzymes that work together to help to form these traps, known as NETs.
Neutrophils generate reactive oxygen-containing molecules and then undergo cell death, releasing the NETs. Arturo Zychlinsky and his team at the Max Planck Institute for Infection Biology in Berlin tested neutrophil extracts for their ability to unwind DNA and disrupt the cell nucleus — key steps in NET formation.
They homed in on two enzymes, neutrophil elastase and myeloperoxidase, that are normally stored in granules. When activated by the oxygen-containing molecules, the enzymes move to the nucleus, where they unwind DNA.