Traditionally, two main types of the cell death (apoptosis and necrosis) are distinguished. The Nomenclature Committee on Cell Death in the last classification of the involved molecular pathways (2018) divided the necrotic and apoptotic morphology of cell death into more than 20 subforms. Besides, earlier it has been also reported about the artificially created cell death pathway.

Apoptosis is a coordinated physiological process of programmed cell death. The cells of the macrophage system should quickly eliminate the dying cells, while producing anti-inflammatory cytokines. During the apoptotic death there is a clear time-dependent sequence of the events initiated by the influence of apoptosis inducer that finally results into the engulf of the apoptotic cell corpses. This is a key sign of the apoptosis that does not cause a damage of the tissue and its inflammation unlike the necrosis.

Necrotic cell death is accompanied by infringement of the plasma membrane integrity and influx of intracellular components into the environment (that causes the inflammation). Recently a new specific type of death has been discovered for neutrophilic granulocytes of blood (neutrophils): Neutrophil Extracellular Traps (NETs). The formation of neutrophil extracellular traps protects the body. Released chromatin immobilizes and neutralizes dangerous and numerically dominant bacteria and help to stop their spreading. NETs can capture another inert material, for example, natural sodium monourate crystals, formed in the case of gout, or artificial nanoparticles, that after contacting with a human body cannot be destroyed or removed (e.g. nanodiamonds or polystyrene nanoparticles). It leads to neutrophils activation and further formation of extracellular neutrophil traps in the place of self-limiting inflammatory process. During some acute inflammatory processes in the internal organs, particularly in the case of acute necrotizing pancreatitis, massive tissue necrosis occurs. Investigation of the internal organs of the patients with the acute inflammation of abdominal cavity allows to examine the interface of the intact and necrotizing tissues and show that necrotizing areas are isolated from the adjacent healthy tissues by aggregated extracellular neutrophil traps.

Aggregated extracellular traps are dense macroscopic structures. It has been found that during excessive infiltration of pancreatic ducts they have been occluded by aggregated extracellular neutrophil traps. At the same time, DNase-1 and DNase-1L3 enzymes-destructors of traps play the important role in protection of vessels from occlusion by neutrophil traps. These two enzymes duplicate each otherfs functions, but when both of them do not function, the blood clots are formed from extracellular neutrophil traps that clog the vessels, and ultimately lead to multiple organ failure and/or death. The smallest capillaries in the lungs are undergo this destructive effect first of all.

Despite the importance of detecting neutrophil extracellular traps, they are often ignored in the routine blood tests, while automated hemoanalyzers do not have appropriate commands to detect them. Modern recommendations underline a problem of ignoring unrecognized objects, including newly formed extracellular traps, in the process of cell counting.

Thus, over the past 15 years, the issue of the extracellular neutrophil traps formation has become extremely important. Current studies convincingly prove the importance of these structures. Extracellular neutrophil traps help not only to stop the spreading of bacteria or to neutralize the objects that are too large for phagocytosis, but they also help to isolate the damaged (necrotic) tissues. At the same time, problems that lead to accumulation of neutrophil traps can trigger multiple organ failure or death.

Article recieved: 25.05.2018

Keywords: neutrophil extracellular traps, inflammation, apoptosis, necrosis

Full text: PDF (Ukr)

1. 1. Bilyy R. Structural and functional changes in the surface of mammalian cells undergoing apoptosis and their role in intercellular interactions and immune response: thesis for a Doctor of Science degree in biology, speciality 03.00.11 ′Сytology, cell biology, histology′′. Lviv; 2015. 395 р.
2. 2. Alberts B, Johnson A, Lewis J, Raff M, Roberts K. Molecular biology of the cell. New York, USA: Garland Science; 2002. 3786 p.
3. 3. Biermann MHC, Podolska MJ, Knopf J, Reinwald C, Weidner D, Maueröder C, et al. Oxidative burst-dependent NETosis is implicated in the resolution of necrosis-associ- ated sterile inflammation. Front Immunol. 2016;7:557. doi.org/10.3389/fimmu.2016.00557
4. 4. Bilyy R, Fedorov V, Vovk V, Leppkes M, Dumych T, Chopyak V, et al. Neutrophil extracellular traps form a barrier between necrot- ic and viable areas in acute abdominal inflammation. Front Immunol. 2016;7:424. doi.org/10.3389/fimmu.2016.00424
5. 5. Bilyy R, Podhorodecki A, Nyk M, Stoika R, Zaichenko A, Zatryb G et al. Utilization of GaN:Eu3+ nanocrystals for the detection of programmed cell death. Phys E Low-dimensional Syst Nanostructures. 2008;40(6):2096-9. doi.org/10.1016/j.physe.2007.09.147
6. 6. Bilyy RO, Shkandina T, Tomin A, Mu-oz LE, Franz S, Antonyuk V et al. Macrophages discriminate glycosylation patterns of apoptotic cell-derived microparticles. J Biol Chem. 2012;287(1):496-503. doi.org/10.1074/jbc.M111.273144
7. 7. Bilyy RO, Stoika RS. Lectinocytochemical detection of apoptotic murine leukemia L1210 cells. Cytometry A. 2003;56(2):89-95. doi.org/10.1002/cyto.a.10089
8. 8. Bilyy R, Stoika R. Search for novel cell surface markers of apoptotic cells. Autoimmunity. 2007;40(4):249- 53. doi.org/10.1080/08916930701358867
9. 9. Bilyy R, Tomyn A, Kit Y, Podhorodecki A, Misiewicz J, Nyk M et al. Detection of dying cells using lectin-conjugated fluorescent and luminescent nanoparticles. Materialwissenschaft und Werkstofftechnik. 2009. 234-7. doi.org/10.1002/mawe.200900432
10. 10. Brinkmann V, Reichard U, Goosmann C, Fauler B, Uhlemann Y, Weiss DS et al. Neutrophil extracellular traps kill bacteria. Science. 2004;303(5663):1532-5. doi.org/10.1126/science.1092385
11. 11. Bunting H. Interstitial desoxyribonucleic acid following cell death. Yale J Biol Med. 1950;22(6):521-5.
12. 12. Casciola-Rosen LA, Anhalt G, Rosen A. Autoantigens targeted in systemic lupus erythematosus are clustered in two populations of surface structures on apoptotic keratinocytes. J Exp Med. 1994;179(4):1317-30. doi.org/10.1084/jem.179.4.1317
13. 13. Caudrillier A, Kessenbrock K, Gilliss BM, Nguyen JX, Marques MB, Monestier M et al. Platelets induce neutrophil extracellular traps in transfusion-related acute lung injury. J Clin Invest. 2012;122(7):2661-71. doi.org/10.1172/JCI61303
14. 14. Douda DN, Khan MA, Grasemann H, Palaniyar N. SK3 channel and mitochondrial ROS mediate NADPH oxidase-independent NETosis induced by calcium influx. Proc Natl Acad Sci USA. 2015;112(9):2817-22. doi.org/10.1073/pnas.1414055112
15. 15. Erwig L-P, Henson PM. Immunological consequences of apoptotic cell phagocytosis. Am J Pathol. 2007;171(1):2-8. doi.org/10.2353/ajpath.2007.070135
16. 16. Fadok VA, Voelker DR, Campbell PA, Cohen JJ, Bratton DL, Henson PM. Exposure of phosphatidylserine on the surface of apoptotic lymphocytes triggers specific recognition and removal by macrophages. J Immunol. 1992;148(7):2207-16.
17. 17. Fuchs TA, Abed U, Goosmann C, Hurwitz R, Schulze I, Wahn V et al. Novel cell death program leads to neutrophil extracellular traps. J Cell Biol. 2007;176(2):231-41. doi.org/10.1083/jcb.200606027
18. 18. Galluzzi L, Vitale I, Aaronson SA, Abrams JM, Adam D, Agostinis P et al. Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018. Cell Death Differ. 2018;25(3):486-541. doi.org/10.1038/s41418-017-0012-4
19. 19. Gloude NJ, Khandelwal P, Luebbering N, Lounder DT, Jodele S, Alder MN et al. Circulating dsDNA, endothelial injury, and complement activation in thrombotic microangiopathy and GVHD. Blood. 2017;130(10):1259-66. doi.org/10.1182/blood-2017-05-782870
20. 20. Gurusamy KS, Pallari E, Hawkins N, Pereira SP, Davidson BR. Management strategies for pancreatic pseudocysts. Cochrane Database Syst Rev. 2016;4:CD011392.
21. 21. Hakkim A, Fürnrohr BG, Amann K, Laube B, Abed UA, Brinkmann V et al. Impairment of neutrophil extracellular trap degradation is associated with lupus nephritis. Proc Natl Acad Sci USA. 2010;107(21):9813-8. doi.org/10.1073/pnas.0909927107
22. 22. Hochreiter-Hufford A, Ravichandran KS. Clearing the dead: apoptotic cell sensing, recognition, engulfment, and digestion. Cold Spring Harb Perspect Biol. 2013;5(1):a008748. doi.org/10.1101/cshperspect.a008748
23. 23. Hotchkiss RS, Strasser A, McDunn JE, Swanson PE. Cell death. N Engl J Med. 2009;361(16):1570-83. doi.org/10.1056/NEJMra0901217
24. 24. Janko C, Munoz L, Chaurio R, Maueröder C, Berens C, Lauber K et al. Navigation to the graveyard-induction of various pathways of necrosis and their classification by flow cytometry. Methods Mol Biol. 2013;1004:3-15. doi.org/10.1007/978-1-62703-383-1_1
25. 25. Jiao Y, Li Z, Loughran PA, Fan EK, Scott MJ, Li Y et al. Frontline Science: Macrophage-derived exosomes promote neutrophil necroptosis following hemorrhagic shock. J Leukoc Biol. 2018;103(2):175-83.
26. 26. Jiménez-Alcázar M, Rangaswamy C, Panda R, Bitterling J, Simsek YJ, Long AT et al. Host DNases prevent vascular occlusion by neutrophil extracellular traps. Science. 2017;358(6367):1202-6. doi.org/10.1126/science.aam8897
27. 27. Kaminskyy V, Kulachkovskyy O, Stoika R. A decisive role of mitochondria in defining rate and intensity of apoptosis induction by different alkaloids. Toxicol Lett. 2008;177(3):168-81. doi.org/10.1016/j.toxlet.2008.01.009
28. 28. Kenny EF, Herzig A, Krüger R, Muth A, Mondal S, Thompson PR et al. Diverse stimuli engage different neutrophil extracellular trap pathways. Elife. 2017;6:e24437. doi.org/10.7554/eLife.24437
29. 29. Khandpur R, Carmona-Rivera C, Vivekanandan-Giri A, Gizinski A, Yalavarthi S, Knight JS et al. NETs are a source of citrullinated autoantigens and stimulate inflammatory responses in rheumatoid arthritis. Sci Transl Med. 2013;5(178):178ra40. doi.org/10.1126/scitranslmed.3005580
30. 30. Konig MF, Abusleme L, Reinholdt J, Palmer RJ, Teles RP, Sampson K, et al. Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis. Sci Transl Med. 2016;8(369):369ra176. doi.org/10.1126/scitranslmed.aaj1921
31. 31. Konig MF, Andrade F. A critical reappraisal of neutrophil extracellular traps and NETosis mimics based on differential requirements for protein citrullination. Front Immunol. 2016;7:461. doi.org/10.3389/fimmu.2016.00461
32. 32. Lauber K, Blumenthal SG, Waibel M, Wesselborg S. Clearance of apoptotic cells: getting rid of the corpses. Mol Cell. 2004;14(3):277-87. doi.org/10.1016/S1097-2765(04)00237-0
33. 33. Lawen A. Apoptosis-an introduction. Bioessays. 2003;25(9):888-96. doi.org/10.1002/bies.10329
34. 34. Leppkes M, Maueröder C, Hirth S, Nowecki S, Günther C, Billmeier U et al. Externalized decondensed neutrophil chromatin occludes pancreatic ducts and drives pancreatitis. Nat Commun. 2016;7:10973. doi.org/10.1038/ncomms10973
35. 35. Malachowa N, Kobayashi SD, Freedman B, Dorward DW, DeLeo FR. Staphylococcus aureus leukotoxin GH promotes formation of neutrophil extracellular traps. J Immunol. 2013;191(12):6022-9. doi.org/10.4049/jimmunol.1301821
36. 36. Manfredi AA, Ramirez GA, Rovere-Querini P, Maugeri N. The Neutrophil's Choice: Phagocytose vs Make Neutrophil Extracellular Traps. Front Immunol. 2018;9:288. doi.org/10.3389/fimmu.2018.00288
37. 37. Maueröder C, Chaurio RA, Dumych T, Podolska M, Lootsik MD, Culemann S et al. A blast without power - cell death induced by the tuberculosis-necrotizing toxin fails to elicit adequate immune responses. Cell Death Differ. 2016;23(6):1016-25. doi.org/10.1038/cdd.2016.4
38. 38. Mercer J, Helenius A. Virus entry by macropinocytosis. Nat Cell Biol. 2009;11(5):510-20. doi.org/10.1038/ncb0509-510
39. 39. Munoz LE, Bilyy R, Biermann MH, Kienhöfer D, Maueröder C, Hahn J et al. Nanoparticles size-dependently initiate self-limiting NETosis-driven inflammation. Proc Natl Acad Sci USA. 2016;113(40):E5856-65. doi.org/10.1073/pnas.1602230113
40. 40. Munoz LE, Lauber K, Schiller M, Manfredi A, Herrmann M. The role of defective clearance of apoptotic cells in systemic autoimmunity. Nat Rev Rheumatol. 2010;6(5):280-9. doi.org/10.1038/nrrheum.2010.46
41. 41. Munoz LE, Maueröder C, Chaurio R, Berens C, Herrmann M, Janko C et al. Colourful death: six-pa- rameter classification of cell death by flow cytometry-dead cells tell tales. Autoimmunity. 2013;46(5):336-41. doi.org/10.3109/08916934.2012.755960
42. 42. Neeli I, Radic M. Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release. Front Immunol. 2013;4:38. doi.org/10.3389/fimmu.2013.00038
43. 43. Proskuryakov SY, Konoplyannikov AG, Gabai VL. Necrosis: a specific form of programmed cell death? Exp Cell Res. 2003;283(1):1-16. doi.org/10.1016/S0014-4827(02)00027-7
44. 44. Reutelingsperger CP, Reutelingsperger CP, Christiaan Peter M. Method for detecting and/or optionally quantifying and/or separating apoptotic cells in or from a sample. United States; 1998:1-9.
45. 45. Romero V, Fert-Bober J, Nigrovic PA, Darrah E, Haque UJ, Lee DM et al. Immune-mediated pore-forming pathways induce cellular hypercitrullination and generate citrullinated autoantigens in rheumatoid arthritis. Sci Transl Med. 2013;5(209):209ra150. doi.org/10.1126/scitranslmed.3006869
46. 46. Rosado CJ, Kondos S, Bull TE, Kuiper MJ, Law RHP, Buckle AM et al. The MACPF/CDC family of pore-forming toxins. Cell Microbiol. 2008;10(9):1765-74. doi.org/10.1111/j.1462-5822.2008.01191.x
47. 47. Schauer C, Janko C, Munoz LE, Zhao Y, Kienhöfer D, Frey B et al. Aggregated neutrophil extracellular traps limit inflammation by degrading cytokines and chemokines. Nat Med. 2014;20(5):511-7. doi.org/10.1038/nm.3547
48. 48. Shkandina T, Herrmann M, Bilyy R. Sweet kiss of dying cell: Sialidase activity on apoptotic cell is able to act toward its neighbors. Autoimmunity. 2012;45(8):574-8. doi.org/10.3109/08916934.2012.719951
49. 49. Sur Chowdhury C, Giaglis S, Walker UA, Buser A, Hahn S, Hasler P. Enhanced neutrophil extracellular trap generation in rheumatoid arthritis: analysis of underlying signal transduction pathways and potential diagnostic utility. Arthritis Res Ther. 2014;16(3):R122. doi.org/10.1186/ar4579
50. 50. Tomin A, Dumych T, Kril I, Antonyuk V, Chopyak V, Stoika R et al. Magnetic separation of apoptotic cells with lectin-conjugated microparticles. Materwiss Werksttech. 2016;47:189-92. doi.org/10.1002/mawe.201600470
51. 51. Tomin A, Dumych T, Tolstyak Y, Kril I, Mahorivska I, Bila E et al. Desialylation of dying cells with catalytically active antibodies possessing sialidase activity facilitate their clearance by human macrophages. Clin Exp Immunol. 2015;179(1):17-23. doi.org/10.1111/cei.12312
52. 52. Vainio T, Koskimies O, Perlmann P, Perlmann H, Klein G. In vitro cytotoxic effect of lymphoid cells from mice immunized with allogeneic tissue. Nature. 1964;204:453-5. doi.org/10.1038/204453a0
53. 53. Vanlangenakker N, Vanden Berghe T, Krysko DV, Festjens N, Vandenabeele P. Molecular mechanisms and pathophysiology of necrotic cell death. Curr Mol Med. 2008;8(3):207-20. doi.org/10.2174/156652408784221306
54. 54. van Zandbergen G, Bollinger A, Wenzel A, Kamhawi S, Voll R, Klinger M et al. Leishmania disease development depends on the presence of apoptotic promastigotes in the virulent inoculum. Proc Natl Acad Sci USA. 2006;103(37):13837-42. doi.org/10.1073/pnas.0600843103
55. 55. Verhoven B, Schlegel RA, Williamson P. Mechanisms of phosphatidylserine exposure, a phagocyte recognition signal, on apoptotic T lymphocytes. J Exp Med. 1995;182(5):1597-601. doi.org/10.1084/jem.182.5.1597
56. 56. Villanueva E, Yalavarthi S, Berthier CC, Hodgin JB, Khandpur R, Lin AM et al. Netting neutrophils induce endothelial damage, infiltrate tissues, and expose immunostimulatory molecules in systemic lupus erythematosus. J Immunol. 2011;187(1):538-52. doi.org/10.4049/jimmunol.1100450