Anaplasma phagocytophilum ligation to toll-like receptor (TLR) 2, but not to TLR4, activates macrophages for nuclear factor-kappa B nuclear translocation.
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.
Choi
Kyoung-Seong
KS
Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Scorpio
Diana G
DG
Dumler
J Stephen
JS
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
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