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 degrees 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 degrees 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 degrees C. The depletion of plasmalemmal cholesterol with methyl beta-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.
Department of Anatomy I, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan. rnomura@fujita-hu.ac.jp
Ryuji
R
Nomura
Asuka
A
Kiyota
Etsuko
E
Suzaki
Katsuko
K
Kataoka
Yoshihide
Y
Ohe
Kaoru
K
Miyamoto
Takao
T
Senda
Toyoshi
T
Fujimoto
D000595:Amino Acid Sequence; D000818:Animals; D018826:CD13 Antigens / Q000378:metabolism*; D021941:Caveolae / Q000821:virology*; D051242:Caveolin 1; D022461:Caveolins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D028941:Coronavirus 229E, Human / Q000378:metabolism / Q000472:pathogenicity*; D005347:Fibroblasts / Q000821:virology; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D034622:RNA Interference; D034741:RNA, Small Interfering; D011991:Receptors, Virus / Q000378:metabolism; D012867:Skin / Q000166:cytology
C495540:CAV1 protein, human; D051242:Caveolin 1; D022461:Caveolins; D034741:RNA, Small Interfering; D011991:Receptors, Virus; D018826:CD13 Antigens