LÄHDE: Virology. 2009 Jan 20;383(2):237-47. doi: 10.1016/j.virol.2008.10.029. Epub 2008 Nov 14. Requirements for cell rounding and surface protein down-regulation by Ebola virus glycoprotein.
Abstract
Ebola
virus causes an acute hemorrhagic fever that is associated with high
morbidity and mortality. The viral glycoprotein is thought to contribute
to pathogenesis, though precise mechanisms are unknown. Cellular
pathogenesis can be modeled in vitro by expression of the Ebola
viral glycoprotein (GP) in cells, which causes dramatic morphological
changes, including cell rounding and surface protein down-regulation.
These effects are known to be dependent on the presence of a highly
glycosylated region of the glycoprotein, the mucin domain. Here we show
that the mucin domain from the highly pathogenic Zaire subtype of Ebola
virus is sufficient to cause characteristic cytopathology when
expressed in the context of a foreign glycoprotein. Similarly to full
length Ebola
GP, expression of the mucin domain causes rounding, detachment from the
extracellular matrix, and the down-regulation of cell surface levels of
beta1 integrin and major histocompatibility complex class 1. These
effects were not seen when the mucin domain was expressed in the context
of a glycophosphatidylinositol-anchored isoform of the foreign
glycoprotein. In contrast to earlier analysis of full length Ebola
glycoproteins, chimeras carrying the mucin domains from the Zaire and
Reston strains appear to cause similar levels of down-modulation and
cell detachment. Cytopathology associated with Ebola
glycoprotein expression does not occur when GP expression is restricted
to the endoplasmic reticulum. In contrast to a previously published
report, our results demonstrate that GP-induced surface protein
down-regulation is not mediated through a dynamin-dependent pathway.
Overall, these results support a model in which the mucin domain of Ebola GP acts at the cell surface to induce protein down modulation and cytopathic effects.
- PMID:
- 19013626
- [PubMed - indexed for MEDLINE]
- PMCID:
- PMC2654768
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