title: Leukotriene B4 amplifies eosinophil accumulation in response to nematodes.
abstract: Eosinophil accumulation is a defining feature of the immune response to parasitic worm infection. Tissue-resident cells, such as epithelial cells, are thought to initiate eosinophil recruitment. However, direct recognition of worms by eosinophils has not been explored as a mechanism for amplifying eosinophil accumulation. Here, we report that eosinophils rapidly migrate toward diverse nematode species in three-dimensional culture. These include the mammalian parasite Nippostrongylus brasiliensis and the free-living nematode Caenorhabditis elegans. Surprisingly, collective migration toward worms requires paracrine leukotriene B4 signaling between eosinophils. In contrast, neutrophils show a minimal response to nematodes, yet are able to undergo robust leukotriene-dependent migration toward IgG-coated beads. We further demonstrate that eosinophils accumulate around C. elegans in the lungs of mice. This response is not dependent on bacterial products, CCR3, or complement activation. However, mice deficient in leukotriene signaling show markedly attenuated eosinophil accumulation after injection of C. elegans or N. brasiliensis. Our findings establish that nematode-derived signals can directly induce leukotriene production by eosinophils and that leukotriene signaling is a major contributor to nematode-induced eosinophil accumulation in the lung. The similarity of the eosinophil responses to diverse nematode species suggests that conserved features of nematodes are recognized during parasite infection.
authors.affiliation: Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Patnode
authors.affiliation: Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Bando
authors.affiliation: Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Krummel
authors.affiliation: Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Locksley
authors.affiliation: Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143Department of Anatomy, Program in Biomedical Sciences, Howard Hughes Medical Institute, Department of Medicine, and Department of Pathology, University of California, San Francisco, San Francisco, CA 94143 steven.rosen@ucsf.edu.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Rosen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000276:immunology; D002465:Cell Movement / Q000235:genetics / Q000276:immunology*; D004804:Eosinophils / Q000276:immunology* / Q000502:physiology; D007074:Immunoglobulin G / Q000276:immunology; D007975:Leukotriene B4 / Q000235:genetics / Q000276:immunology*; D008168:Lung / Q000276:immunology* / Q000469:parasitology / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009559:Nippostrongylus / Q000276:immunology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D017206:Strongylida Infections / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007975:Leukotriene B4