关键词: 人, 细胞融合, CD46

Abstract: Objective To observe cell fusion from without(FFWO) induced by human herpesvirus 6(HHV-6). Methods Cells were overlaid with 10⁵　HHV-6-infected CBMCs (nearly 80% positive for HHV-6 late antigen by IFA) or infected with cell-free HHV-6 at 10^3-4TCID₅₀ for 60 minutes and the cells were stained with HE 2-3 days after infection.To determine whether HHV-6A induced FFWO or not, Vero cells (5×10⁵ per well) were overlaid with 10⁵ HHV-6-infected CBMCs (nearly 90% positive for HHV-6 late antigen by IFA) or infected with cell-free HHV-6 at 10^3-4 TCID₅₀ for 60 minutes, and cultured with medium supplemented with PFA (300 mg•L^-1), fixed 24 hours after infection;Vero or MT4 cells were infected with cell-free virus (HHV-6A or HHV-6B) for 1 hour, and cycloheximide was added to a final concentration of 100 mg•L^-1. After incubation at 37℃ for 2 hours, the cells were fixed and stained with HE. Results The syncytia formation induced by HHV-6A was observed 2 hours after infection; moreover, it was found in the presence of cycloheximide, indicating that HHV-6A induced FFWO in the target cells. Furthermore, the fusion event was dependent on the expression of the HHV-6 entry receptor, CD46, on the target cells membrane. Conclusion HHV-6A can induce FFWO in a variety of human cells through its entry receptor, CD46.

Key words: human, cell fusion, CD46