Frontline Science: Aggregated neutrophil extracellular traps prevent inflammation on the neutrophil-rich ocular surface

Mahajan A, Grüneboom A, Petru L, Podolska M, Kling L, Maueröder C, Dahms F, Christiansen S, Günter L, Krenn V, Jünemann A, Bock F, Schauer C, Schett G, Hohberger B, Herrmann M, Munoz LE (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Journal of Leukocyte Biology Society for Leukocyte Biology

DOI: 10.1002/JLB.HI0718-249RR

Abstract

Eye rheum is a physiological discharge, which accumulates at the medial angle of the healthy eye soon after opening in the morning. Microscopic evaluation of eye rheum revealed the presence of viable neutrophils, bacteria, epithelial cells, and particles, aggregated by neutrophil extracellular traps. We observed that in the evening, during eye closure, high C5a recruited neutrophils to the tear film and activated them. In this hypoxic area rich in CO 2 , neutrophils fight microbial aggressors by degranulation. Immediately after eye opening, the microenvironment of the ocular surface changes, the milieu gets normoxic, and loss of CO 2 induces subtle alkalinization of tear film. These conditions favored the formation of neutrophil extracellular traps (NETs) that initially covers the ocular surface and tend to aggregate by eyelid blinking. These aggregated neutrophil extracellular traps (aggNETs) are known as eye rheum and contain several viable neutrophils, epithelial cells, dust particles, and crystals packed together by NETs. Similar to aggNETs induced by monosodium urate crystals, the eye rheum shows a robust proteolytic activity that degraded inflammatory mediators before clinically overt inflammation occur. Finally, the eye rheum passively floats with the tear flow to the medial angle of the eye for disposal. We conclude that the aggNETs-based eye rheum promotes cleaning of the ocular surface and ameliorates the inflammation on the neutrophil-rich ocular surfaces.

Authors with CRIS profile

Aparna Mahajan Department of Medicine 3 – Rheumatology and Immunology Malgorzata Podolska Department of Medicine 3 – Rheumatology and Immunology Christian Maueröder Department of Medicine 3 – Rheumatology and Immunology Georg Schett Lehrstuhl für Innere Medizin III Bettina Hohberger Institut für Anatomie Martin Herrmann Department of Medicine 3 – Rheumatology and Immunology Luis Munoz Becerra Department of Medicine 3 – Rheumatology and Immunology

Involved external institutions

Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE) Universität zu Köln DE Germany (DE) Kerckhoff-Klinik DE Germany (DE) Universitätsmedizin Rostock DE Germany (DE)

How to cite

APA:

Mahajan, A., Grüneboom, A., Petru, L., Podolska, M., Kling, L., Maueröder, C.,... Munoz, L.E. (2019). Frontline Science: Aggregated neutrophil extracellular traps prevent inflammation on the neutrophil-rich ocular surface. Journal of Leukocyte Biology. https://dx.doi.org/10.1002/JLB.HI0718-249RR

MLA:

Mahajan, Aparna, et al. "Frontline Science: Aggregated neutrophil extracellular traps prevent inflammation on the neutrophil-rich ocular surface." Journal of Leukocyte Biology (2019).

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