title: Neutrophil extracellular traps are induced by Mycobacterium tuberculosis.
abstract: Due to the intracellular nature of mycobacterial infections, little attention has been paid to the possible extracellular role that neutrophils might play in tuberculosis. The recent discovery of neutrophil extracellular traps (NETs), composed of DNA and antimicrobial proteins,(1) introduces a new perspective to our understanding of the mechanism used by the innate immune system to contain and kill microorganisms. In this study, we tested in vitro whether Mycobacterium tuberculosis, an intracellular pathogen, can induce NETs formation and if this newly discovered mechanism is involved in a control response during mycobacterial infection. We found that two different genotypes of M. tuberculosis exerted, in vitro, a cytotoxic effect and induced subcellular changes on infected neutrophils, leading to NETs formation in a time dependent manner. NETs trapped mycobacteria but were unable to kill them. NETs formation induced by M. tuberculosis could help understand the early stages of mycobacterial pathogenesis.
authors.affiliation: Depto. de Inmunología, Escuela Nacional de Ciencias Biológicas, I.P.N., Carpio y Plan de Ayala s/n. Col. Santo Tomás, México, D.F., México. vramosk@yahoo.com.mx
authors.forename: Victoria
authors.initials: V
authors.lastname: Ramos-Kichik
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mondragón-Flores
authors.forename: Mónica
authors.initials: M
authors.lastname: Mondragón-Castelán
authors.forename: Sirenia
authors.initials: S
authors.lastname: Gonzalez-Pozos
authors.forename: Sae
authors.initials: S
authors.lastname: Muñiz-Hernandez
authors.forename: Oscar
authors.initials: O
authors.lastname: Rojas-Espinosa
authors.forename: Rommel
authors.initials: R
authors.lastname: Chacón-Salinas
authors.forename: Sergio
authors.initials: S
authors.lastname: Estrada-Parra
authors.forename: Iris
authors.initials: I
authors.lastname: Estrada-García
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D004247:DNA / Q000032:analysis; D005110:Extracellular Space / Q000276:immunology*; D005456:Fluorescent Dyes; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D007113:Immunity, Innate; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000472:pathogenicity* / Q000648:ultrastructure; D009504:Neutrophils / Q000382:microbiology / Q000502:physiology* / Q000648:ultrastructure; D010587:Phagocytosis; D013194:Staining and Labeling; D014376:Tuberculosis / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D037521:Virulence Factors; D004247:DNA