Neutrophil

For organisms that grow in neutral pH environments, see Neutrophile.

Neutrophil
3D rendering of a neutrophil
Neutrophils with segmented nuclei surrounded by erythrocytes and platelets. Intra-cellular granules are visible in the cytoplasm (Giemsa stained).
Details
SystemImmune system
FunctionPhagocytosis
Identifiers
MeSHD009504
THH2.00.04.1.02012
FMA62860
Anatomical terms of microanatomy

Neutrophils are a type of phagocytic white blood cell and part of innate immunity. More specifically, they form the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans.[1] Their functions vary in different animals.[2] They are also known as neutrocytes, heterophils or polymorphonuclear leukocytes.

They are formed from stem cells in the bone marrow and differentiated into subpopulations of neutrophil-killers and neutrophil-cagers. They are short-lived (between 5 and 135 hours, see § Life span) and highly mobile, as they can enter parts of tissue where other cells/molecules cannot. Neutrophils may be subdivided into segmented neutrophils and banded neutrophils (or bands). They form part of the polymorphonuclear cells family (PMNs) together with basophils and eosinophils.[3][4][5]

The name neutrophil derives from staining characteristics on hematoxylin and eosin (H&E) histological or cytological preparations. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, neutrophils stain a neutral pink. Normally, neutrophils contain a nucleus divided into 2–5 lobes.[6]

Neutrophils are a type of phagocyte and are normally found in the bloodstream. During the beginning (acute) phase of inflammation, particularly as a result of bacterial infection, environmental exposure,[7] and some cancers,[8][9] neutrophils are one of the first responders of inflammatory cells to migrate toward the site of inflammation. They migrate through the blood vessels and then through interstitial space, following chemical signals such as interleukin-8 (IL-8), C5a, fMLP, leukotriene B4, and hydrogen peroxide (H2O2)[10] in a process called chemotaxis. They are the predominant cells in pus, accounting for its whitish/yellowish appearance.[11]

Neutrophils are recruited to the site of injury within minutes following trauma and are the hallmark of acute inflammation.[12] They not only play a central role in combating infection but also contribute to pain in the acute period by releasing pro-inflammatory cytokines and other mediators that sensitize nociceptors, leading to heightened pain perception.[13] However, due to some pathogens being indigestible, they may not be able to resolve certain infections without the assistance of other types of immune cells.

  1. ^ Actor J (2012). Elsevier's Integrated Review Immunology and Microbiology (Second ed.). doi:10.1016/B978-0-323-07447-6.00002-8.
  2. ^ Ermert D, Niemiec MJ, Röhm M, Glenthøj A, Borregaard N, Urban CF (August 2013). "Candida albicans escapes from mouse neutrophils". Journal of Leukocyte Biology. 94 (2): 223–236. doi:10.1189/jlb.0213063. PMID 23650619. S2CID 25619835.
  3. ^ Witko-Sarsat V, Rieu P, Descamps-Latscha B, Lesavre P, Halbwachs-Mecarelli L (May 2000). "Neutrophils: molecules, functions and pathophysiological aspects". Laboratory Investigation; A Journal of Technical Methods and Pathology. 80 (5): 617–653. doi:10.1038/labinvest.3780067. PMID 10830774. S2CID 22536645.
  4. ^ Klebanoff SJ, Clark RA (1978). The Neutrophil: Function and Clinical Disorders. Elsevier/North-Holland Amsterdam. ISBN 978-0-444-80020-6.
  5. ^ Nathan C (March 2006). "Neutrophils and immunity: challenges and opportunities". Nature Reviews. Immunology. 6 (3): 173–182. doi:10.1038/nri1785. PMID 16498448. S2CID 1590558.
  6. ^ Welsh CJ (2021). Hole's Essentials of Human Anatomy and Physiology (14th ed.). New York, USA: McGraw Hill. p. 336. ISBN 978-1-260-57521-7. Retrieved 28 February 2023.
  7. ^ Jacobs L, Nawrot TS, de Geus B, Meeusen R, Degraeuwe B, Bernard A, et al. (October 2010). "Subclinical responses in healthy cyclists briefly exposed to traffic-related air pollution: an intervention study". Environmental Health. 9 (64): 64. Bibcode:2010EnvHe...9...64J. doi:10.1186/1476-069X-9-64. PMC 2984475. PMID 20973949.
  8. ^ Waugh DJ, Wilson C (November 2008). "The interleukin-8 pathway in cancer". Clinical Cancer Research. 14 (21): 6735–6741. doi:10.1158/1078-0432.CCR-07-4843. PMID 18980965. S2CID 9415085.
  9. ^ De Larco JE, Wuertz BR, Furcht LT (August 2004). "The potential role of neutrophils in promoting the metastatic phenotype of tumors releasing interleukin-8". Clinical Cancer Research. 10 (15): 4895–4900. doi:10.1158/1078-0432.CCR-03-0760. PMID 15297389. S2CID 9782495.
  10. ^ Yoo SK, Starnes TW, Deng Q, Huttenlocher A (November 2011). "Lyn is a redox sensor that mediates leukocyte wound attraction in vivo". Nature. 480 (7375): 109–112. Bibcode:2011Natur.480..109Y. doi:10.1038/nature10632. PMC 3228893. PMID 22101434.
  11. ^ Barer MR (2012). "The natural history of infection". Medical Microbiology. Elsevier. pp. 168–173. doi:10.1016/b978-0-7020-4089-4.00029-9. ISBN 978-0-7020-4089-4.
  12. ^ Cohen S, Burns RC (2002). Pathways of the Pulp (8th ed.). St. Louis: Mosby. p. 465.
  13. ^ Huerta MÁ, Molina-Álvarez M, García MM, Tejada MA, Goicoechea C, Ghasemlou N, et al. (2024-10-25). "The role of neutrophils in pain: systematic review and meta-analysis of animal studies". Pain. doi:10.1097/j.pain.0000000000003450. ISSN 0304-3959.