title: Alternative activation of macrophages by filarial nematodes is MyD88-independent.
abstract: Alternative macrophage activation is largely defined by IL-4Rα stimulation but the contribution of Toll-like receptor (TLR) signaling to this phenotype is not currently known. We have investigated macrophage activation status under Th2 conditions in the absence of the core TLR adaptor molecule, MyD88. No impairment was observed in the ability of MyD88-deficient bone marrow derived macrophages to produce or express alternative activation markers, including arginase, RELM-α or Ym1, in response to IL-4 treatment in vitro. Further, we observed no difference in the ability of peritoneal exudate cells from nematode implanted wild type (WT) or MyD88-deficient mice to produce arginase or express the alternative activation markers RELM-α or Ym1. Therefore, MyD88 is not a fundamental requirement for Th2-driven macrophage alternative activation, either in vitro or in vivo.
authors.affiliation: The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
authors.forename: Katie J
authors.initials: KJ
authors.lastname: Mylonas
authors.forename: Marieke A
authors.initials: MA
authors.lastname: Hoeve
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDonald
authors.forename: Judith E
authors.initials: JE
authors.lastname: Allen
mesh_terms: D000818:Animals; D001119:Arginase / Q000235:genetics / Q000276:immunology; D017178:Brugia malayi / Q000276:immunology*; D005368:Filariasis / Q000276:immunology*; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology; D037102:Lectins / Q000235:genetics / Q000276:immunology; D008262:Macrophage Activation / Q000235:genetics / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology / Q000473:pathology; D001619:beta-N-Acetylhexosaminidases / Q000235:genetics / Q000276:immunology; D053662:Interleukin-4 Receptor alpha Subunit
chemical_list: D001119:Arginase; D036341:Intercellular Signaling Peptides and Proteins; D037102:Lectins; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface; D001619:beta-N-Acetylhexosaminidases; C504002:Il4ra protein, mouse; D053662:Interleukin-4 Receptor alpha Subunit; C507780:Myd88 protein, mouse; C413576:Retnla protein, mouse; C429541:Chil3 protein, mouse