title: Anaplasma phagocytophilum, interferon gamma production and Stat1 signaling.
abstract: Human granulocytic anaplasmosis is caused by the obligate intracellular bacterium, Anaplasma phagocytophilum. The proinflammatory cytokine, IFN-γ, is necessary for innate immunity and plays an important role in the induction of severe histopathology in A. phagocytophilum-infected mice, horses and humans. In this study, activation of signal transducer and activator of transcription (Stat) 1 phosphorylation associated with A. phagocytophilum infection was examined in mice and found to be markedly greater on day 7 post-infection than in mock-infected controls. This increase in phosphorylated Stat1 (pStat1) correlated significantly with IFN-γ production and inflammatory tissue injury. Because pStat1 operates as a transcription factor central to the generation of effectors of inflammatory injury, these data suggest that Stat1 signaling is involved in IFN-γ-mediated immunopathologic lesions and disease in A. phagocytophilum infection and could be an important target for intervention in this disease.
authors.affiliation: College of Ecology and Environmental Science, School of Animal Science and Biotechnology, Kyungpook National University, Sangju 742-711, Korea.
authors.forename: Kyoung-Seong
authors.initials: KS
authors.lastname: Choi
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Dumler
mesh_terms: D041081:Anaplasma phagocytophilum / Q000276:immunology*; D000818:Animals; D004195:Disease Models, Animal; D016873:Ehrlichiosis / Q000276:immunology*; D005260:Female; D007371:Interferon-gamma / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D050794:STAT1 Transcription Factor / Q000096:biosynthesis*; D015398:Signal Transduction
chemical_list: D050794:STAT1 Transcription Factor; C494080:Stat1 protein, mouse; D007371:Interferon-gamma