Abstract
Background
Otitis media (OM), a prevalent pediatric infectious disease, is mainly caused by Streptococcus pneumoniae (S.pn). Neutrophil extracellular traps (NETs), a novel antimicrobial strategy, were reported in 2004. We found that NETs formed in the middle ear with acute otitis media (AOM) induced by S.pn. However, the mechanisms of NETs formation are not entirely clear.
Methods
We stimulated neutrophils isolated from mouse bone marrow with S.pn clinical stain 19F in vitro, and established mouse model of AOM via transbullar injection with S.pn. NETs formation, reactive oxygen species (ROS) production, autophagy activation and bacterial load were analyzed in TLR4−/− and wild-type neutrophils stimulated in vitro with S.pn and in vivo during AOM.
Results
We found that autophagy and ROS were required for S.pn-induced NETs formation. Moreover, TLR4 partly mediated NETs formation in response to S.pn in vitro and in vivo during AOM. We also showed that attenuated NETs formation in TLR4−/− neutrophils correlated with an impaired ROS production and autophagy activation in vitro and in vivo. In addition, both the in vivo and in vitro-produced NETs were able to engulf and kill S.pn.
Conclusions
TLR4 regulates ROS and autophagy to control NETs formation against S.pn in the course of AOM.
Impact
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S.pn can induce NETs formation in vitro and in vivo; TLR4 regulates NETs formation by ROS and autophagy; NETs contribute to the clearance of bacteria in acute otitis media.
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In this study, we firstly found that autophagy and ROS were required for S.pn-induced NETs formation in the model of acute otitis media (AOM). And to some extent, TLR4 mediated NETs formation during AOM.
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Our research might provide a potential strategy for the treatment of otitis media.
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References
Taylor, S., Marchisio, P. & Vergison, A. Impact of pneumococcal conjugate vaccination on otitis media: a systematic review. Clin. Infect. Dis. 54, 1765–1773 (2012).
Wang, W., Zhou, A. & Zhang, X. Interleukin 17A promotes pneumococcal clearance by recruiting neutrophils and inducing apoptosis through a p38 mitogen-activated protein kinase-dependent mechanism in acute otitis media. Infect. Immun. 82, 2368–2377 (2014).
Brinkmann, V. Neutrophil extracellular traps kill bacteria. Science 303, 1532–1535 (2004).
Remijsen, Q., Berghe, T. V. & Wirawan, E. Neutrophil extracellular trap cell death requires both autophagy and superoxide generation. Cell Res. 21, 290–304 (2011).
Schachern, P. A., Kwon, G. & Briles, D. E. Neutrophil extracellular traps and fibrin in otitis media: analysis of human and chinchilla temporal bones. JAMA Otolaryngol. Head Neck Surg. 143, 990–995 (2017).
Stoiber, W., Obermayer, A. & Steinbacher, P. The tole of reactive oxygen species (ROS) in the formation of extracellular traps (ETs) in humans. Biomolecules 5, 702–723 (2015).
Kirchner, T., Möller, Sonja & Klinger, M. The impact of various reactive oxygen species on the formation of neutrophil extracellular traps. Mediators Inflamm. 2012, 849136 (2012).
Yost, C. C., Cody, M. J. & Harris, E. S. Impaired neutrophil extracellular trap (NET) formation: a novel innate immune deficiency of human neonates. Blood 113, 6419–6427 (2009).
Van Avondt, Van dLM & Naccache, P. H. Signal inhibitory receptor on leukocytes-1 limits the formation of neutrophil extracellular traps, but preserves intracellular bacterial killing. J. Immunol. 196, 3686–3694 (2016).
Kenny, E. F., Herzig, A. & Renate, Krüger Diverse stimuli engage different neutrophil extracellular trap pathways. Elife 6pii, e24437 (2017).
Nakagawa, I., Amano, A. & Mizushima, N. Autophagy defends cells against invading group A Streptococcus. Science 306, 1037–1040 (2004).
Jones, S. A., Mills, K. H. & Harris, J. Autophagy and inflammatory diseases. Immunol. Cell Biol. 91, 250–258 (2013).
Itakura, A. & Mccarty, O. J. T. Pivotal role for the mTOR pathway in the formation of neutrophil extracellular traps via regulation of autophagy. Am. J. Physiol. Cell Physiol. 305, C348–C354 (2013).
Park, S. Y., Shrestha, S. & Youn, Y. J. Autophagy primes neutrophils for neutrophil extracellular trap formation during sepsis. Am. J. Respir. Crit. Care Med. 196, 577–589 (2017).
Mcinturff, A. M., Cody, M. J. & Elliott, E. A. Mammalian target of rapamycin regulates neutrophil extracellular trap formation via induction of hypoxia-inducible factor 1α. Blood 120, 3118–3125 (2012).
Kumar, H., Kawai, T. & Akira, S. Toll-like receptors and innate immunity. Biochem. Biophys. Res. Commun. 388, 621–625 (2009).
Sabroe, I., Prince, L. R. & Jones, E. C. Selective roles for Toll-like receptor (TLR)2 and TLR4 in the regulation of neutrophil activation and life span. J. Immunol. 170, 5268–5275 (2003).
Oklu, R., Albadawi, H. & Jones, J. E. Reduced hind limb ischemia-reperfusion injury in Toll-like receptor-4 mutant mice is associated with decreased neutrophil extracellular traps. J. Vasc. Surg. 58, 1627–1636 (2013).
Tadie, J. M., Bae, H. B. & Jiang, S. HMGB1 promotes neutrophil extracellular trap formation through interactions with Toll-like receptor 4. Am. J. Physiol. Lung Cell Mol. Physiol. 304, L342–L349 (2013).
Mitroulis, I., Kourtzelis, I. & Kambas, K. Regulation of the autophagic machinery in human neutrophils. Eur. J. Immunol. 40, 1461–1472 (2010).
Xu, F., Zhang, C. & Zou, Z. Aging-related Atg5 defect impairs neutrophil extracellular traps formation. Immunology 151, 417–432 (2017).
Huang, Y., Wang, Z. & Jin, C. TLR2 promotes macrophage recruitment and S.pneumoniae clearance during mouse otitis media. Pediatr. Res. 80, 886–893 (2016).
Allen, L. A. Immunofluorescence and confocal microscopy of neutrophils. Methods Mol. Biol. 1124, 251–268 (2014).
Xiang, Y., Jin, C. & Wang, W. The critical role of myeloperoxidase in streptococcus pneumoniae clearance and tissue damage during mouse acute otitis media. Innate Immun. 23, 296–306 (2017).
Urban, C. F., Reichard, U. & Brinkmann, V. Neutrophil extracellular traps capture and kill Candida albicans yeast and hyphal forms. Cell Microbiol. 8, 668–676 (2010).
Reid, S., Hong, W. & Dew, K. Streptococcus pneumoniae forms surface-attached communities in the middle ear of experimentally infected chinchillas. J. Infect. Dis. 199, 786–794 (2009).
Short, K. R., von Köckritz-Blickwede, M. & Langereis, J. D. Antibodies mediate formation of neutrophil extracellular traps in the middle ear and facilitate secondary pneumococcal otitis media. Infect. Immun. 82, 364–370 (2014).
Ma, Y. H., Ma, T. & Wang, C. High-mobility group box 1 potentiates antineutrophil cytoplasmic antibody-inducing neutrophil extracellular traps formation. Arthritis Res Ther. 18, 2 (2016).
Saitoh, T., Komano, J. & Saitoh, Y. Neutrophil extracellular traps mediate a host defense response to human immunodeficiency virus-1. Cell Host Microbe 12, 109–116 (2012).
Huang, H., Tohme, S. & Alkhafaji, A. B. Damage-associated molecular pattern-activated neutrophil extracellular trap exacerbates sterile inflammatory liver injury. Hepatology 62, 600–614 (2015).
Metzler, K., Goosmann, C. & Lubojemska, A. A myeloperoxidase-containing complex regulates neutrophil elastase release and actin dynamics during NETosis. Cell Rep. 8, 883–896 (2014).
Arai, Y., Nishinaka, Y. & Arai, T. Uric acid induces NADPH oxidase-independent neutrophil extracellular trap formation. Biochem. Biophys. Res. Commun. 443, 556–561 (2014).
Pilsczek, F. H., Salina, D. & Poon, K. K. H. A novel mechanism of rapid nuclear neutrophil extracellular trap formation in response to staphylococcus aureus. J. Immunol. 185, 7413–7425 (2010).
Chargui, A., Cesaro, A. & Mimouna, S. Subversion of autophagy in adherent invasive escherichia coli-Infected neutrophils induces inflammation and cell death. PLoS ONE 7, e51727 (2012).
Li, P., Li, M. & Lindberg, M. R. PAD4 is essential for antibacterial innate immunity mediated by neutrophil extracellular traps. J. Exp. Med. 207, 1853–1862 (2010).
Dewaele, M., Maes, H. & Agostinis, P. ROS-mediated mechanisms of autophagy stimulation and their relevance in cancer therapy. Autophagy 6, 838–854 (2010).
Sharma, A., Simonson, T. J. & Jondle, C. N. Mincle-mediated neutrophil extracellular trap formation by regulation of autophagy. J. Infect. Dis. 215, 1040–1048 (2017).
Beiter, K., Wartha, F. & Albiger, B. An endonuclease allows streptococcus pneumoniae to escape from neutrophil extracellular traps. Curr. Biol. 16, 401–407 (2006).
Wartha, F., Beiter, K. & Albiger, B. Capsule and d-alanylated lipoteichoic acids protect Streptococcus pneumoniae against neutrophil extracellular traps. Cell Microbiol. 9, 1162–1171 (2010).
Acknowledgements
This work was supported by the National Natural Science Foundation Grants of China (No. csfc81373151) and Natural Science Foundation Project of CQCSTC (Nos. cstc2012jjA0035, cstc2018jcyjAX0257).
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Y.H. and Y.D. conceived of and designed the research. Y.D., C.J., Y.Z., Q.H., X.Z. and Z.D. performed the experiments and analyzed the data. Y.H., Z.D. and Y.D. wrote the manuscript. R.A. and Y.Y. interpreted the data.
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Dong, Y., Jin, C., Ding, Z. et al. TLR4 regulates ROS and autophagy to control neutrophil extracellular traps formation against Streptococcus pneumoniae in acute otitis media. Pediatr Res 89, 785–794 (2021). https://doi.org/10.1038/s41390-020-0964-9
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DOI: https://doi.org/10.1038/s41390-020-0964-9
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