title: Extracellular vesicles from Leishmania-infected macrophages confer an anti-infection cytokine-production profile to naïve macrophages.
abstract: BACKGROUND
  Extracellular vesicles (EVs) are structures with phospholipid bilayer membranes and 100-1000 nm diameters. These vesicles are released from cells upon activation of surface receptors and/or apoptosis. The production of EVs by dendritic cells, mast cells, macrophages, and B and T lymphocytes has been extensively reported in the literature. EVs may express MHC class II and other membrane surface molecules and carry antigens. The aim of this study was to investigate the role of EVs from Leishmania-infected macrophages as immune modulatory particles.
  
  
  RESULTS
  In this work it was shown that BALB/c mouse bone marrow-derived macrophages, either infected in vitro with Leishmania amazonensis or left uninfected, release comparable amounts of 50-300 nm-diameter extracellular vesicles (EVs). The EVs were characterized by flow cytometry and electron microscopy. The incubation of naïve macrophages with these EVs for 48 hours led to a statistically significant increase in the production of the cytokines IL-12, IL-1β, and TNF-α.
  
  
  CONCLUSIONS
  EVs derived from macrophages infected with L. amazonensis induce other macrophages, which in vivo could be bystander cells, to produce the proinflammatory cytokines IL-12, IL-1β and TNF-α. This could contribute both to modulate the immune system in favor of a Th1 immune response and to the elimination of the Leishmania, leading, therefore, to the control the infection.
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Cronemberger-Andrade
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Aragão-França
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Cintia Figueiredo
authors.initials: CF
authors.lastname: de Araujo
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Viviane Junqueira
authors.initials: VJ
authors.lastname: Rocha
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Mariana da Cruz
authors.initials: Mda C
authors.lastname: Borges-Silva
authors.forename: Cláudio P
authors.initials: CP
authors.lastname: Figueira
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Cláudio P
authors.initials: CP
authors.lastname: Figueiras
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Oliveira
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Luiz A R
authors.initials: LA
authors.lastname: de Freitas
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Patrícia S T
authors.initials: PS
authors.lastname: Veras
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: Lain
authors.initials: L
authors.lastname: Pontes-de-Carvalho
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D000067128:Extracellular Vesicles / Q000276:immunology*; D007891:Leishmania / Q000276:immunology* / Q000469:parasitology*; D007896:Leishmaniasis / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C