Figure 6.

Cell-Cell Membrane Fusion Induced by EHV-1

(A) Fusion between PBMC and EC was visualized using confocal laser scanning microscope. Expression of mRFP protein is indicated by red and EHV-1 GFP replication is represented by green after GFP expression, which is integrated in the viral genome. Colocalization of both colors is shown in the merge panel. Data are representative of two independent experiments. Scale bar, 10 μm, and scale bar of magnification, 7 μm. Image stacks (number of stacks = 17 with 0.75 μm z stack step size) were photographed using VisiScope Confocal FRAP microscope. Presented here is a single optical section of the stacks.

(B) Fusion between infected PBMC and EC was further detected by luciferase activity. Results are shown as means of three independent and blinded experiments with standard errors and are presented as luciferase luminescence unit (RLU). The asterisk indicates p value <0.05 using Kruskal-Wallis test followed by Dunns test for multiple comparisons. Infected PBMC only (Inf_PBMC + Trans_EC) and transfected PBMC only (Trans_PBMC + Trans_EC) were used as negative controls. Control positive is represented by transfected PBMC with both plasmids (double Trans_PBMC). Trans_inf_PBMC + Trans_EC:PBMC was transfected with T7 RNA polymerase-encoding plasmid, then infected with EHV-1 GFP, and overlaid on EC transfected with a plasmid encoding luciferase gene under a T7 promoter. See also Figure S11.