Plasticity of neutrophils reveals modulatory capacity

Abstract

Neutrophils are widely known as proinflammatory cells associated with tissue damage and for their early arrival at sites of infection, where they exert their phagocytic activity, release their granule contents, and subsequently die. However, this view has been challenged by emerging evidence that neutrophils have other activities and are not so short-lived. Following activation, neutrophil effector functions include production and release of granule contents, reactive oxygen species (ROS), and neutrophil extracellular traps (NETs). Neutrophils have also been shown to produce a wide range of cytokines that have pro- or anti-inflammatory activity, adding a modulatory role for this cell, previously known as a suicide effector. The presence of cytokines almost always implies intercellular modulation, potentially unmasking interactions of neutrophils with other immune cells. In fact, neutrophils have been found to help B cells and to modulate dendritic cell (DC), macrophage, and T-cell activities. In this review, we describe some ways in which neutrophils influence the inflammatory environment in infection, cancer, and autoimmunity, regulating both innate and adaptive immune responses. These cells can switch phenotypes and exert functions beyond cytotoxicity against invading pathogens, extending the view of neutrophils beyond suicide effectors to include functions as regulatory and suppressor cells.

Indoleamine 2,3‐dioxygenase and tryptophan 2,3‐dioxygenase expression in HPV infection, SILs, and cervical cancer

“…IDO‐positive leukocytes identified in cervical samples from HPV‐infected women showed a typical neutrophil morphology. The role of neutrophil in the cervix may be associated to their response in various inflammation contexts . Initially, neutrophils were recognized as a single population; however, several neutrophil subtypes have now been identified .…”

Characterization of neutrophil‐to‐lymphocyte ratio as a measure of inflammation in rheumatoid arthritis

“…Cytokine profiling in RA patients and its comparison with inflammatory variables indicated that changes in cytokines were not related to variations in NLR. Quantitation of granulocyte colony stimulating factor (G‐CSF) and granulocyte/macrophage colony stimulating factor (GM‐CSF), (markers of general inflammation and neutrophils) could have provided a better assessment of NLR variations . The present study considered only remission patients for the cytokine sub‐study.…”

“…Quantitation of granulocyte colony stimulating factor (G-CSF) and granulocyte/macrophage colony stimulating factor (GM-CSF), (markers of general inflammation and neutrophils) could have provided a better assessment of NLR variations. [25][26][27] The present study considered only remission patients for the cytokine sub-study. Additional studies involving NLR sub-groups are required to determine its usefulness in patients with different disease activities.…”

Induced CNS expression of CXCL1 augments neurologic disease in a murine model of multiple sclerosis via enhanced neutrophil recruitment

“…Nonetheless, there is increasing interest in the potential role of other cell types, including neutrophils, in participating in demyelination. The diverse functions of neutrophils include phagocytosis, release of toxic granules, and secretion of ROS, nitrogen species, and neutrophil extracellular traps that can lead to bacterial clearance and tissue damage . In addition, neutrophils can produce many different cytokines and chemokines that participate in tailoring the immune response as well as enhancing neuroinflammation .…”

“…The diverse functions of neutrophils include phagocytosis, release of toxic granules, and secretion of ROS, nitrogen species, and neutrophil extracellular traps that can lead to bacterial clearance and tissue damage . In addition, neutrophils can produce many different cytokines and chemokines that participate in tailoring the immune response as well as enhancing neuroinflammation . Although there is direct evidence that neutrophils are important in both disease initiation and progression in EAE models only indirect evidence exists showing these cells also play a role in MS pathogenesis .…”