Expression of ICAM-1 on the Hantaan virus-infected human umbilical vein endothelial cells

Abstract

Objectives: In HFRS, there is a varying degree of disseminated intravascular coagulation which was evident in the early phase of the illness. It is believed also that DIC would be the consequence, at least in part, of functional changes of endothelium resulting in kinin activation and clinical syndrome. This study investigated the role of adhesion molecule in the pathogenesis of Hantaan virus-related disease.

Methods: The expression of ICAM-1 antigen on the cell membrane of human umbilical vein endothelial cells was assessed by immunohistochemistry, and ICAM-1 mRNA in the endothelial cells was assessed by in situ hybridization after Hantaan virus infection (2.6 x 10(4) PFU/mL) with the time course.

Results: In immunohistochemistry, the number of ICAM-1 positive cells increased with time during the 12 or 24 hours after infection. 5 to 10% of HUVECs had been positive after 12-24 hours and the number of positive cells decreased abruptly after 24 hours. Hantaan antigen had been noticed after 12 hours focally on the HUVECs but continued to proliferate into day 7 post-infection when most of HUVECs were infected by Hantaan virus. In situ hybridization showed identical patterns of ICAM-1 mRNA expression after Hantaan virus infection.

Conclusion: It implies that the Hantaan virus infection on HUVECs would express more ICAM-1 on their surface and implicated in the pathogenesis of early clinical syndrome of HFRS.

Fig. 1.

Plaque assay for Hantaan virus. Dilution factors in the well of above plate were 1:25, 1:250, 1:2,500, 1:25,000, and negative control from the top of the left.

Fig. 2.

Immunohistochemistry against Hantaan antigen on HUVECs: (a) irradiated virus inoculated, 6 days later, (b-e) Hantaan virus inoculated, 12 hours, 1 day, 3 days, and 7 days later, respectively. Characteristic intracytoplasmic granular color reactions that were noticed in a small number of cells (b and c; arrow) increased with time. By day 7 after infection, almost all cells had Hantaan antigen.

Fig. 3.

Immunohistochemistry against ICAM-1 on HUVECs; (a-d) Hantaan virus inoculated, 6 hours, 12 hours, 24 hours and 4 days later, respectively, (e) TNF-α stimulated in the concentration of 200 ng/mL for 6 hours, (f) irradiated virus inoculated, 12 hours later.

Fig. 4.

In situ hybridization against mRNA of ICAM-1 on HUVECs; (a-d) Hantaan virus inoculated, 6 hours, 12 hours, 24 hours, and 4 days later, respectively, (e) TNF-α stimulated in the concentration of 200 ng/mL for 6 hours, (f) irradiated virus inoculated, 12 hours later.

Fig. 5.

In situ hybridization against mRNA of ICAM-1 on HUVECs that had grown on the Thermanox®; (a) Hantaan virus inoculated, 12 hours later, (b) TNF-α stimulated in the concentration of 200 ng/mL for 6 hours, (c) irradiated virus inoculated, 12 hours later.