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Eosinophil granulocyte

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Title: Eosinophil granulocyte  
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Subject: Granulocyte, Interleukin, Eosinophilic esophagitis, Neutrophil granulocyte, White blood cell
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Eosinophil granulocyte

Eosinophil granulocyte
Eosinophil under the microscope (400x) from a peripheral blood smear. Red blood cells surround the eosinophil, two platelets at the top left corner.
Identifiers
Code TH H2.00.04.1.02017
Anatomical terminology
3D Rendering of Eosinophil

Eosinophil granulocytes, usually called eosinophils or eosinophiles (or, less commonly, acidophils), are white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. Along with mast cells, they also control mechanisms associated with allergy and asthma. They are granulocytes that develop during hematopoiesis in the bone marrow before migrating into blood.

These cells are eosinophilic or 'acid-loving' as shown by their affinity to coal tar dyes: Normally transparent, it is this affinity that causes them to appear brick-red after staining with eosin, a red dye, using the Romanowsky method. The staining is concentrated in small granules within the cellular cytoplasm, which contain many chemical mediators, such as histamines and proteins such as eosinophil peroxidase, ribonuclease (RNase), deoxyribonucleases (DNase), lipase, plasminogen, and major basic protein. These mediators are released by a process called degranulation following activation of the eosinophil, and are toxic to both parasite and host tissues.

In normal individuals, eosinophils make up about 1-6% of white blood cells, and are about 12-17

  • Eosinophil - BioWeb at University of Wisconsin System
  • Histology at ucsf.edu
  • "What is an eosinophil?" at the Cincinnati Center for Eosinophilic Disorders

External links

  1. ^ Young, Barbara; Lowe, joseph o'connell; Stevens, Alan; Heath, John W. (2006). Wheater's Functional Histology (5 ed.). Elsevier Limited.  
  2. ^ Young, Barbara; Lowe, James S.; Stevens, Alan; Heath, John W. (2006). Wheater's Functional Histology (5 ed.). Elsevier Limited.  
  3. ^ Metcalf D, Begley C, Nicola N, Johnson G (1987). "Quantitative responsiveness of murine hemopoietic populations in vitro and in vivo to recombinant multi-CSF (IL-3)". Exp Hematol 15 (3): 288–95.  
  4. ^ Metcalf D, Burgess A, Johnson G, Nicola N, Nice E, DeLamarter J, Thatcher D, Mermod J (1986). "In vitro actions on hemopoietic cells of recombinant murine GM-CSF purified after production in Escherichia coli: comparison with purified native GM-CSF". J Cell Physiol 128 (3): 421–31.  
  5. ^ Yamaguchi Y, Suda T, Suda J, Eguchi M, Miura Y, Harada N, Tominaga A, Takatsu K (1988). "Purified interleukin 5 supports the terminal differentiation and proliferation of murine eosinophilic precursors". J Exp Med 167 (1): 43–56.  
  6. ^ Wagner LA, Christensen CJ, Dunn DM; et al. (June 2007). "EGO, a novel, noncoding RNA gene, regulates eosinophil granule protein transcript expression". Blood 109 (12): 5191–8.  
  7. ^ Trulson A, Byström J, Engström A, Larsson R, Venge P (2007). "The functional heterogeneity of eosinophil cationic protein is determined by a gene polymorphism and post-translational modifications". Clin Exp Allergy 37 (2): 208–18.  
  8. ^ a b Hogan S, Rosenberg H, Moqbel R, Phipps S, Foster PS, Lacy P, Kay AB, Rothenberg ME (2008). "Eosinophils: Biological Properties and Role in Health and Disease". Clin Exp Allergy 38 (5): 709–50.  
  9. ^ Lacy P (2005). "The role of Rho GTPases and SNAREs in mediator release from granulocytes". Pharmacol Ther 107 (3): 358–76.  
  10. ^ Saito K, Nagata M, Kikuchi I, Sakamoto Y (2004). "Leukotriene D4 and eosinophil transendothelial migration, superoxide generation, and degranulation via beta2 integrin". Ann Allergy Asthma Immunol 93 (6): 594–600.  
  11. ^ Bandeira-Melo C, Bozza P, Weller P (2002). "The cellular biology of eosinophil eicosanoid formation and function". J Allergy Clin Immunol 109 (3): 393–400.  
  12. ^ Kato Y, Fujisawa T, Nishimori H, Katsumata H, Atsuta J, Iguchi K, Kamiya H (2005). "Leukotriene D4 induces production of transforming growth factor-beta1 by eosinophils". Int Arch Allergy Immunol. 137. Suppl 1 (1): 17–20.  
  13. ^ Horiuchi T, Weller P (1997). "Expression of vascular endothelial growth factor by human eosinophils: upregulation by granulocyte macrophage colony-stimulating factor and interleukin-5". Am J Respir Cell Mol Biol 17 (1): 70–7.  
  14. ^ a b c d Rothenberg M, Hogan S (2006). "The eosinophil". Annu Rev Immunol 24 (1): 147–74.  
  15. ^ Shi H (2004). "Eosinophils function as antigen-presenting cells". J Leukoc Biol 76 (3): 520–7.  
  16. ^ Gleich G, Adolphson C (1986). "The eosinophilic leukocyte: structure and function". Adv Immunol 39: 177–253.  
  17. ^ Slifman N, Loegering D, McKean D, Gleich G (1986). "Ribonuclease activity associated with human eosinophil-derived neurotoxin and eosinophil cationic protein". J Immunol 137 (9): 2913–7.  
  18. ^ Zheutlin L, Ackerman S, Gleich G, Thomas L (1984). "Stimulation of basophil and rat mast cell histamine release by eosinophil granule-derived cationic proteins". J Immunol 133 (4): 2180–5.  
  19. ^ Morgan R, Costello R, Durcan N, Kingham P, Gleich G, McLean W, Walsh M (2005). "Diverse effects of eosinophil cationic granule proteins on IMR-32 nerve cell signaling and survival". Am J Respir Cell Mol Biol 33 (2): 169–77.  
  20. ^ Young J, Peterson C, Venge P, Cohn Z (1986). "Mechanism of membrane damage mediated by human eosinophil cationic protein". Nature 321 (6070): 613–6.  
  21. ^ Venge P, Byström J, Carlson M, Hâkansson L, Karawacjzyk M, Peterson C, Sevéus L, Trulson A (1999). "Eosinophil cationic protein (ECP): molecular and biological properties and the use of ECP as a marker of eosinophil activation in disease". Clin Exp Allergy 29 (9): 1172–86.  

References

See also

Additional images

Treatments used to combat autoimmune diseases and conditions caused by eosinophils include:

Treatment

Reference ranges for blood tests of white blood cells, comparing eosinophil granulocyte amount (shown in light red) with other cells.

An increase in eosinophils, i.e., the presence of more than 500 eosinophils/microlitre of blood is called an eosinophilia, and is typically seen in people with a parasitic infestation of the intestines, collagen vascular disease (such as rheumatoid arthritis), malignant diseases such as Hodgkin's disease, extensive skin diseases (such as exfoliative dermatitis), Addison's disease, reflux esophagitis (in which eosinophils will be found in the squamous epithelium of the esophagus), eosinophilic esophagitis, and with the use of certain drugs such as penicillin. But, perhaps the most common cause for eosinophilia is an allergic condition such as asthma. In 1989, contaminated L-tryptophan supplements caused a deadly form of eosinophilia known as eosinophilia-myalgia syndrome, which was reminiscent of the Toxic Oil Syndrome in Spain in 1981.

Eosinophilia

Major basic protein, eosinophil peroxidase, and eosinophil cationic protein are toxic to many tissues.[14] Eosinophil cationic protein and eosinophil-derived neurotoxin are ribonucleases with antiviral activity.[17] Major basic protein induces mast cell and basophil degranulation, and is implicated in peripheral nerve remodelling.[18][19] Eosinophil cationic protein creates toxic pores in the membranes of target cells allowing potential entry of other cytotoxic molecules to the cell,[20] can inhibit proliferation of T cells, suppress antibody production by B cells, induce degranulation by mast cells, and stimulate fibroblast cells to secrete mucus and glycosaminoglycan.[21] Eosinophil peroxidase forms reactive oxygen species and reactive nitrogen intermediates that promote oxidative stress in the target, causing cell death by apoptosis and necrosis.[14]

Following activation by an immune stimulus, eosinophils degranulate to release an array of cytotoxic granule cationic proteins that are capable of inducing tissue damage and dysfunction.[16] These include:

Granule proteins

In addition, there are also eosinophils that play a role in fighting viral infections, which is evident from the abundance of RNases they contain within their granules, and in fibrin removal during inflammation. Eosinophils along with basophils and mast cells, are important mediators of allergic responses and asthma pathogenesis and are associated with disease severity. They also fight helminth (worm) colonization and may be slightly elevated in the presence of certain parasites. Eosinophils are also involved in many other biological processes, including postpubertal mammary gland development, oestrus cycling, allograft rejection and neoplasia.[14] They have also recently been implicated in antigen presentation to T cells.[15]

Following activation, eosinophils effector functions include production of:

Function

Eosinophils develop and mature in the bone marrow. They differentiate from myeloid precursor cells in response to the cytokines interleukin 3 (IL-3), interleukin 5 (IL-5), and granulocyte macrophage-colony stimulating factor (GM-CSF).[3][4][5] Eosinophils produce and store many secondary granule proteins prior to their exit from the bone marrow. After maturation, eosinophils circulate in blood and migrate to inflammatory sites in tissues, or to sites of helminth infection in response to chemokines like CCL11 (eotaxin-1), CCL24 (eotaxin-2), CCL5 (RANTES), 5-hydroxyicosatetraenoic acid and 5-oxo-eicosatetraenoic acid, and certain leukotrienes like leukotriene B4 (LTB4) and MCP1/4. At these infectious sites, eosinophils are activated by Type 2 cytokines released from a specific subset of helper T cells (Th2); IL-5, GM-CSF, and IL-3 are important for eosinophil activation as well as maturation. There is evidence to suggest that eosinophil granule protein expression is regulated by the non-coding RNA EGOT (gene)[6]

Development, migration and activation

Contents

  • Development, migration and activation 1
  • Function 2
  • Granule proteins 3
  • Eosinophilia 4
  • Treatment 5
  • Additional images 6
  • See also 7
  • References 8
  • External links 9

Pioneering work in the 1980s elucidated that eosinophils were unique granulocytes, having the capacity to survive for extended periods of time after their maturation as demonstrated by ex-vivo culture experiments. [2]

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