title: Mycobacterium tuberculosis H37Rv induces ectosome release in human polymorphonuclear neutrophils.
abstract: Ectocytosis, the cellular process by which ectosomes (Ects) are released, is an important phenomenon by which eukaryotic cells exchange molecular information. Ects released from N-formylmethionyl-leucyl-phenylalanine (fMLP)-activated human polymorphonuclear neutrophils (PMNs) have recently been characterized. Molecules such as CD35 and phosphatidylserine (PS), and enzymes such as myeloperoxidase and elastase were found in these vesicles, suggesting that Ects from PMNs could function as ecto-organelles with anti-microbial activity. Here we show for the first time that human PMNs release ectosomes in response to Mycobacterium tuberculosis H37Rv infection. We found that the release of ectosomes was not associated exclusively with mycobacterial infection since infection with other microorganisms (e.g., Leishmania mexicana, Staphylococcus aureus, and Escherichia coli or activation with phorbol myristate acetate (PMA)) also induced ectocytosis. Ects release started as early as 10min after infection or activation. Expression of CD35, PS, Rab5, Rab7 and gp91(Phox), a subunit of Cyt b555 was demonstrated on the Ects membrane. Based on our observations we conclude that Ects are released from human neutrophils in response to cell activation and that this process is not related to apoptosis.
authors.affiliation: Depto. de Inmunología, Escuela Nacional de Ciencias Biológicas, I.P.N., Prol. de Carpio y Plan de Ayala s/n. Col. Santo Tomás, México, D.F. 11340, Mexico. jusjo02@yahoo.com.mx <jusjo02@yahoo.com.mx>
authors.forename: Patricia
authors.initials: P
authors.lastname: González-Cano
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mondragón-Flores
authors.forename: Luvia E
authors.initials: LE
authors.lastname: Sánchez-Torres
authors.forename: Sirenia
authors.initials: S
authors.lastname: González-Pozos
authors.forename: Mayra
authors.initials: M
authors.lastname: Silva-Miranda
authors.forename: Amalia
authors.initials: A
authors.lastname: Monroy-Ostria
authors.forename: Sergio
authors.initials: S
authors.lastname: Estrada-Parra
authors.forename: Iris
authors.initials: I
authors.lastname: Estrada-García
mesh_terms: D053148:Caspase 3 / Q000378:metabolism; D055252:Cell-Derived Microparticles / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D005089:Exocytosis / Q000235:genetics / Q000276:immunology; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008853:Microscopy; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D018375:Neutrophil Activation; D009504:Neutrophils / Q000378:metabolism*
chemical_list: D016207:Cytokines; D053148:Caspase 3