title: Wolbachia lipoprotein stimulates innate and adaptive immunity through Toll-like receptors 2 and 6 to induce disease manifestations of filariasis.
abstract: Wolbachia endosymbiotic bacteria have been implicated in the inflammatory pathogenesis of filariasis. Inflammation induced by Brugia malayi female worm extract (BMFE) is dependent on Toll-like receptors 2 and 6 (TLR2/6) with only a partial requirement for TLR1. Removal of Wolbachia, lipids, or proteins eliminates all inflammatory activity. Wolbachia bacteria contain the lipoprotein biosynthesis genes Ltg and LspA but not Lnt, suggesting Wolbachia proteins cannot be triacylated, accounting for recognition by TLR2/6. Lipoprotein databases revealed 3-11 potential lipoproteins from Wolbachia. Peptidoglycan-associated lipoprotein (PAL) and Type IV secretion system-VirB6 were consistently predicted, and B. malayi Wolbachia PAL (wBmPAL) was selected for functional characterization. Diacylated 20-mer peptides of wBmPAL (Diacyl Wolbachia lipopeptide (Diacyl WoLP)) showed a near identical TLR2/6 and TLR2/1 usage compared with BMFE and bound directly to TLR2. Diacyl WoLP induced systemic tumor necrosis factor-alpha and neutrophil-mediated keratitis in mice. Diacyl WoLP activated monocytes induce up-regulation of gp38 on human lymphatic endothelial cells and induced dendritic cell maturation and activation. Dendritic cells primed with BMFE generated a non-polarized Th1/Th2 CD4+ T cell profile, whereas priming with Wolbachia depleted extracts (following tetracycline treatment; BMFEtet) polarized to a Th2 profile that could be reversed by reconstitution with Diacyl WoLP. BMFE generated IgG1 and IgG2c antibody responses, whereas BMFEtet or inoculation of TLR2 or MyD88-/- mice produced defective IgG2c responses. Thus, in addition to innate inflammatory activation, Wolbachia lipoproteins drive interferon-gamma-dependent CD4+ T cell polarization and antibody switching.
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Turner
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: R Stuart
authors.initials: RS
authors.lastname: Langley
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Johnston
authors.affiliation: Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio 44106.
authors.forename: Katrin
authors.initials: K
authors.lastname: Gentil
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Louise
authors.initials: L
authors.lastname: Ford
authors.affiliation: New England Biolabs, Ipswich, Massachusetts 01938.
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Maia
authors.initials: M
authors.lastname: Graham
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Faye
authors.initials: F
authors.lastname: Sharpley
authors.affiliation: New England Biolabs, Ipswich, Massachusetts 01938.
authors.forename: Barton
authors.initials: B
authors.lastname: Slatko
authors.affiliation: Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio 44106.
authors.forename: Eric
authors.initials: E
authors.lastname: Pearlman
authors.affiliation: Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002009:Brugia / Q000378:metabolism*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005260:Female; D005368:Filariasis / Q000378:metabolism*; D006801:Humans; D007107:Immune System; D008074:Lipoproteins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D051195:Toll-Like Receptor 2 / Q000378:metabolism*; D051216:Toll-Like Receptor 6 / Q000378:metabolism*; D020577:Wolbachia / Q000378:metabolism*
chemical_list: D008074:Lipoproteins; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6