Description

Neutrophils, which represent about 50-70% of blood leukocytes in humans, are essential effector cells of the innate immune system that circulate as mature or nearly mature cells, and are typically the first leukocytes to be recruited to inflammatory sites. Although their functions have been best studied in the context of infectious diseases, many recent discoveries highlight the fact that neutrophils can also act as key regulators of both acute and chronic sterile inflammatory conditions.

The abundance of neutrophils in the blood allows the direct assessment of their phenotypic and functional properties in human inflammatory diseases. Recent advances in imaging and genetic approaches in mice have also shed new light on the different functions of neutrophils in a broad spectrum of inflammatory processes, such as anaphylaxis, autoimmunity, asthma, endotoxic shock, and tumor progression. It is now clear that neutrophils can amplify inflammation through several mechanisms, including (i) the formation of neutrophil extracellular traps (NETs); (ii) the release of an array of proteases such as neutrophil elastase or myeloperoxidase and other enzymes, as well as (iii) the secretion of cytokines and chemokines. On the other hand, recent evidence also indicates that neutrophils can participate in the resolution of inflammation. In this regard, it has been shown that uptake of apoptotic neutrophils by macrophages is a key initial step to restoring tissue homeostasis.

The aim of this Research Topic is to gather a collection of basic Review articles and Original Research articles on the role of neutrophils in various inflammatory diseases, to increase our knowledge on (i) the molecular mechanisms by which neutrophils are recruited and activated by inflammatory stimuli; (ii) how neutrophils can act both as positive and negative regulators of inflammation, and (iii) whether neutrophils and/or neutrophil-derived products represent potential therapeutic targets for inflammatory diseases. We welcome the submission of Original Research articles, Reviews, Mini-Reviews, Methods, Case Studies and Clinical Trial articles that address, but are not limited to, the following topics:

1. Models and methods to study neutrophil functions in inflammatory diseases.
2. Contribution of neutrophils to the initiation, propagation and resolution of acute and chronic inflammation.
3. Role of neutrophil-derived products in the regulation of inflammation.
4. Neutrophil migration at the site of inflammation.
5. Molecular mechanisms of neutrophil activation by inflammatory stimuli.
6. Novel targets or drugs aimed at modulating neutrophil functions in inflammation.