クリバヤシ フトシ   Futoshi Kuribayashi
  栗林 太
   所属   川崎医科大学  医学部 基礎医学 生化学
   職種   教授
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Anaplasma phagocytophilum inhibits human neutrophil apoptosis via upregulation of bfl-1, maintenance of mitochondrial membrane potential and prevention of caspase 3 activation.
掲載誌名 正式名:Cellular Microbiology
略  称:Cell. Microbiol.
巻・号・頁 7(1),29-38頁
著者・共著者 Ge Yan, Yoshiie Kiyotaka, Kuribayashi Futoshi, Lin Mingqun, Rikihisa Yasuko.
発行年月 2005/01
概要 The inhibition of neutrophil apoptosis plays a central role in human granulocytic anaplasmosis. Intracellular signalling pathways through which the obligatory intracellular bacterium Anaplasma phagocytophilum inhibits the spontaneous apoptosis of human peripheral blood neutrophils were investigated. bfl-1 mRNA levels in uninfected neutrophils after 12 h in culture were reduced to approximately 5-25% of 0 h levels, but remained high in infected neutrophils. The eukaryotic RNA synthesis inhibitor, actinomycin D, prevented the maintenance of bfl-1 mRNA levels by A. phagocytophilum. Differences in mcl-1, bax, bcl-w, bad or bak mRNA levels in infected versus uninfected neutrophils were not remarkable. By using mitochondrial fluorescent dyes, Mitotracker Red and JC-1, it was found that most uninfected neutrophils lost mitochondrial membrane potential after 10-12 h incubation, whereas A. phagocytophilum-infected neutrophils maintained high membrane potential. Caspase 3 activity and the degree of apoptosis were lower in dose-dependent manner in A. phagocytophilum-infected neutrophils at 16 h post infection, as compared to uninfected neutrophils. Anti-active caspase 3 antibody labelling showed less positively stained population in infected neutrophils compared to those in uninfected neutrophils after 12 h incubation. These results suggest that A. phagocytophilum inhibits human neutrophil apoptosis via transcriptional upregulation of bfl-1 and inhibition of mitochondria-mediated activation of caspase 3.