Histopathological vascular changes in hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus include increased vascular permeability, disseminated intravascular coagulation, thrombocytopenia and changes in coagulation activity.
Although
vascular endothelial cells of main target organs such as kidney infected with Hantaan virus are not damaged but swelling of endothelial cells, perivascular exudates and infiltration of mononuclear cells and fresh interstitial hemorrhages are
common,
However, the pathogenesis of cell infiltration and hemorrhages around vascular endothelial cells are not well understood.
Some endothelial cell molecules or vascular adhesins that acts as adhesion moleulces for leukocyte are expressed on endothelial cells close to site of inflammation. However, whether the expression of endothelial adhesion molecules such as
vascular
cell
adhesion molecule-1 (VCAM-1), intercellular adhesion molecule (ICAM-1)and endothelial leukocyte adhesion molecule (ELAM) on vascular endothelial cells are increased by infection with Hantaan virus has not been studied.
In this study, the reiationship between the expression of VCAM-1, ICAM-1 and ELAM and adhesion of mononuclear cells on endothelial cells of human blood vessels infected with Hantaan virus was investigated. The endothelial cells of umbilical vein
was
passaged three times in culture medium and the monolayered cells were infected with 105 pfu/ml of Hantaan virus grcwn in Vero E6 cells cultures. The multiplication of virus in cultured endothelial cells was monitored by immunohistochemistry and
the
expression of adhesion molecules was demonstrated by immunohistochemistry using monoclonal antibodies against VCAM-1, ICAM-1 and ELAM. And in situ hybriditation against ICAM-1 was also performed.
The endothelial adhesion molecules, VCAM and ICAM, were expressed
expressed after 6 hours postinfection, respectively, and their expressions lasted for 72 hours, Similar expression of VCAM and ICAM appeared on endothelial cells by infection with virus, but the expression of ELAM was not recognized up to 72
hours
postinfection. Microscopically, it was noted that many monocuclear cells adhered on endothelial cells infected with viruses. In an electronmicroscopic study, the transendothelial migration of mononuclear cells was observed on monolayered
endothelial
cells infected with virus.
This results suggested that the endothelial adhesion molecules, particulary VCAM and ICAM, might be expressed on endothelial cells by infection with Hantaan virus and these molecules play a key role in the adhesion and extravasation of
inflammatory
cells around blood vessels.
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