ゴルジ装置の三次元構造:共焦点レーザー走査顕微鏡によるブルンナー腺細胞の観察

広島大学(Hiroshima University)博士(医学)Medicinedoctora

ビデオ顕微分析法の開発と好中球刺激応答系解析への応用

広島大学(Hiroshima University)博士(薬学)Pharmacologydoctora

細胞内小器官の直接3D観察

研究期間:平成10-12年度 ; 研究種目:基盤研究C2 ; 課題番号:10670017原著には既発表論文の別刷を含む

The Golgi apparatus of goblet cells in the mouse descending colon : three-dimensional visualization using a confocal laser scanning microscope

The three-dimensional structure of the Golgi apparatus was studied in goblet cells in lectin-stained sections of the mouse descending colon by using a confocal laser scanning microscope. In the lower part of the crypt, the Golgi apparatus formed a dome-or globe-like structure in the supranuclear region. The wall of the dome or the globe had some holes, one of which usually faced toward the nucleus and others toward the apical cytoplasm. Mucous granules seemed to be initially released into the interior of the dome and transported toward the apical cytoplasm through the holes. In the upper part of the crypt, on the other hand, the Golgi apparatus formed a cup- or funnel-like structure with a larger opening toward the cell apex and a smaller opening toward the nucleus. A large mass ofmucous granules occupied the inside of the cup to the apical cytoplasm. It is thought that the accumulation of mucous granules enlarges holes at the ceiling of the dome to form a large opening, which makes the configuration of the Golgi apparatus cup-shaped

Human Coronavirus 229E Binds to CD13 in Rafts and Enters the Cell through Caveolae

CD13, a receptor for human coronavirus 229E (HCoV-229E), was identified as a major component of the Triton X-100-resistant membrane microdomain in human fibroblasts. The incubation of living fibroblasts with an anti-CD13 antibody on ice gave punctate labeling that was evenly distributed on the cell surface, but raising the temperature to 37°C before fixation caused aggregation of the labeling. The aggregated labeling of CD13 colocalized with caveolin-1 in most cells. The HCoV-229E virus particle showed a binding and redistribution pattern that was similar to that caused by the anti-CD13 antibody: the virus bound to the cell evenly when incubated on ice but became colocalized with caveolin-1 at 37°C; importantly, the virus also caused sequestration of CD13 to the caveolin-1-positive area. Electron microscopy confirmed that HCoV-229E was localized near or at the orifice of caveolae after incubation at 37°C. The depletion of plasmalemmal cholesterol with methyl β-cyclodextrin significantly reduced the HCoV-229E redistribution and subsequent infection. A caveolin-1 knockdown by RNA interference also reduced the HCoV-229E infection considerably. The results indicate that HCoV-229E first binds to CD13 in the Triton X-100-resistant microdomain, then clusters CD13 by cross-linking, and thereby reaches the caveolar region before entering cells