Figure 3.

Immunofluorescence microscopy analysis of time-dependent expression of gD-HSV-1 in U937 cells infected with HSV-1 inactivated or not with UV irradiation. (a) U937-pcDNA cells were infected with intact HSV-1 (50 PFU/cell). At the end of 1 h adsorption period, the virus inoculum was removed, the cells were washed, fresh medium was added and samples for the first time point were collected and stained (time 0 p.i.). Residual cells were incubated at 37 °C until samples were collected at the indicated hours p.i. Images were captured using fluorescent filters optimized for detecting Hoechst-stained nuclei (upper line), surface gD-expressing cells (middle line) or merged (lower line). (b) Parallel infection performed as described in (a) on U937-pcDNA cells, but using UV-inactivated HSV-1. (c) Parallel infection performed as described in (a) but using U937-DN-IκB cells as target cells. (d) Parallel infection performed as described in (b) but using U937-DN-IκB cells as target cells