Advances in neutrophil biology: clinical implications.

Many lung diseases are characterized by neutrophil-dominated inflammation; therefore, an understanding of neutrophil function is of considerable importance to respiratory physicians. This review will focus on recent advances in our understanding of how neutrophils are produced, how these cells leave the circulation, the molecular events regulating neutrophil activation and, ultimately, how these cells die and are removed. The neutrophil is now recognized as a highly versatile and sophisticated cell with significant synthetic capacity and an important role in linking the innate and adaptive arms of the immune response. One of the key challenges in conditions such as COPD, bronchiectasis, cystic fibrosis, and certain forms of asthma is how to manipulate neutrophil function in a way that does not compromise antibacterial and antifungal capacity. The possession by neutrophils of a unique repertoire of surface receptors and signaling proteins may make such targeted therapy possible.