title: Anaplasma phagocytophilum ligation to toll-like receptor (TLR) 2, but not to TLR4, activates macrophages for nuclear factor-kappa B nuclear translocation.
abstract: Anaplasma phagocytophilum is an obligate intracellular bacterium that infects neutrophils and causes human anaplasmosis (formerly human granulocytic ehrlichiosis). Interferon (IFN)- gamma causes immunopathology in A. phagocytophilum infection models. Plasma IFN- gamma levels are elevated 4 h after infection in experimentally infected mice, which indicates innate immunity and possible Toll-like receptors (TLRs). The ability of A. phagocytophilum to trigger proinflammatory responses via nuclear factor (NF)- kappa B was tested in TLR2- and TLR4-transfected cell lines and in primary murine macrophages devoid of TLR2 or TLR4. NF- kappa B was activated only through TLR2, which suggests its role in innate immune induction with A. phagocytophilum infections. The role of innate immunity in human anaplasmosis immunopathology requires more study.
authors.affiliation: Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Kyoung-Seong
authors.initials: KS
authors.lastname: Choi
authors.forename: Diana G
authors.initials: DG
authors.lastname: Scorpio
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Dumler
mesh_terms: D041081:Anaplasma phagocytophilum / Q000276:immunology*; D000712:Anaplasmosis / Q000276:immunology*; D000818:Animals; D018988:Bacterial Translocation / Q000276:immunology; D025065:Borrelia burgdorferi / Q000276:immunology; D016466:CHO Cells; D006224:Cricetinae; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H; D016328:NF-kappa B / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology*; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014162:Transfection
chemical_list: D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors