title: Neutrophils extracellular traps damage Naegleria fowleri trophozoites opsonized with human IgG.
abstract: Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack. In this work, we evaluate the capacity of N. fowleri to induce the liberation of NETs by human PMN cells. Neutrophils were cocultured with unopsonized or IgG-opsonized N. fowleri trophozoites. DNA, histone, myeloperoxidase (MPO) and neutrophil elastase (NE) were stained, and the formation of NETs was evaluated by confocal microscopy and by quantifying the levels of extracellular DNA. Our results showed N. fowleri induce the liberation of NETs including release of MPO and NE by human PMN cells as exposure interaction time is increased, but N. fowleri trophozoites evaded killing. However, when trophozoites were opsonized, they were susceptible to the neutrophils activity. Therefore, our study suggests that antibody-mediated PMNs activation through NET formation may be crucial for antimicrobial responses against N. fowleri.
authors.affiliation: Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, D.F., Mexico.
authors.forename: A
authors.initials: A
authors.lastname: Contis-Montes de Oca
authors.affiliation: Proyecto CyMA, UIICSE, UNAM FES Iztacala, Los Reyes Iztacala, Tlalnepantla, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Carrasco-Yépez
authors.affiliation: Laboratorio de Bioquímica, Departamento de Bioquímica, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, D.F., Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Campos-Rodríguez
authors.affiliation: Laboratorio de Bioquímica, Departamento de Bioquímica, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, D.F., Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Pacheco-Yépez
authors.affiliation: Proyecto CyMA, UIICSE, UNAM FES Iztacala, Los Reyes Iztacala, Tlalnepantla, Mexico.
authors.forename: P
authors.initials: P
authors.lastname: Bonilla-Lemus
authors.affiliation: Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, D.F., Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Pérez-López
authors.affiliation: Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, D.F., Mexico.
authors.forename: S
authors.initials: S
authors.lastname: Rojas-Hernández
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D018920:Coculture Techniques; D004247:DNA / Q000378:metabolism; D065206:Extracellular Traps / Q000276:immunology*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D019272:Leukocyte Elastase / Q000378:metabolism; D008590:Meningoencephalitis / Q000276:immunology / Q000469:parasitology; D018613:Microscopy, Confocal; D016848:Naegleria fowleri / Q000276:immunology*; D009297:Nasal Mucosa / Q000469:parasitology; D018375:Neutrophil Activation / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D009195:Peroxidase / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D053058:Trophozoites / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D006657:Histones; D007074:Immunoglobulin G; D004247:DNA; D009195:Peroxidase; D019272:Leukocyte Elastase
keywords: Naegleria fowleri; immunoglobulins; innate immunity; neutrophils