Neutrophils belong to the first responders of our immune system. They circulate in our bodies and hunt in infected tissues to ingest, kill, and digest harmful pathogens. To become such effective killers in the very complex situation of an inflamed tissue, they work together as a collective. They release chemical signals to attract other cells to form clusters of cells and attack as a swarm. Researchers from the Max Planck Institute of Immunobiology and Epigenetics in Freiburg decipher the basic biology of neutrophil swarming and now show that the cells also evolved an intrinsic molecular program to self-limit their swarming activity. The study elucidates how swarming neutrophils become insensitive to their own secreted signals that brought the swarm together in the first place. This process is crucial for the efficient elimination of bacteria in tissues. The body is well protected against invading pathogens by barriers such as the skin. But if you injure yourself and break your skin, pathogens can easily enter your body through the wound and cause severe infections. If this occurs, the innate immune system takes over the first rapid defense with an effective arsenal of cellular weapons infiltrating the wounded tissue in large numbers. As one of the first cell types on the spot, neutrophil granulocytes are recruited within few hours from the bloodstream to the infection site to eliminate potential microbial invaders.

Regards

John
Editorial Assistant
Journal of Medical & Surgical Pathology