title: Proinflammatory clearance of apoptotic neutrophils induces an IL-12(low)IL-10(high) regulatory phenotype in macrophages.
abstract: Clearance of apoptotic exudate neutrophils (efferocytosis) induces either pro- or anti-inflammatory responses in mouse macrophages depending on host genetic background. In this study, we investigated whether neutrophil efferocytosis induces a stable macrophage phenotype that could be recalled by late restimulation with LPS. Bone marrow-derived macrophages previously stimulated by pro- but not anti-inflammatory neutrophil efferocytosis expressed a regulatory/M2b phenotype characterized by low IL-12 and high IL-10 production following restimulation, increased expression of LIGHT/TNF superfamily 14, Th2-biased T cell responses, and permissive replication of Leishmania major. Induction of regulatory/M2b macrophages required neutrophil elastase activity and was partially dependent on TLR4 signaling. These results suggested that macrophage differentiation to a regulatory phenotype plays a role in resolution of inflammation but could contribute to increased humoral Ab responses and parasite persistence in the infected host.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: Filardy
authors.forename: Dayana R
authors.initials: DR
authors.lastname: Pires
authors.forename: Marise P
authors.initials: MP
authors.lastname: Nunes
authors.forename: Christina M
authors.initials: CM
authors.lastname: Takiya
authors.forename: Celio G
authors.initials: CG
authors.lastname: Freire-de-Lima
authors.forename: Flavia L
authors.initials: FL
authors.lastname: Ribeiro-Gomes
authors.forename: George A
authors.initials: GA
authors.lastname: DosReis
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D002478:Cells, Cultured; D007249:Inflammation / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology; D016753:Interleukin-10 / Q000378:metabolism*; D018664:Interleukin-12 / Q000378:metabolism*; D018320:Leishmania major / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000276:immunology / Q000469:parasitology; D019272:Leukocyte Elastase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000166:cytology / Q000276:immunology*; D009569:Nitric Oxide / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D016753:Interleukin-10; D018664:Interleukin-12; D009569:Nitric Oxide; D007371:Interferon-gamma; D019272:Leukocyte Elastase