FIG. 8.

Characterization and molecular reactivation of HSV-1 in mouse fetal hippocampal cells from latently infected mothers. Female mice were infected intraperitoneally with 10⁶ PFU of HSV-1 (KOS strain) and mated at 37 days postinfection with mock-infected male mice. Hippocampal cells were obtained from fetuses at 18 days of gestation and plated and analyzed after 1 day in vitro. (A) Culture characterized to identify the cell type where the viral signal was detected. For this purpose, immunofluorescence analysis was performed by using anti-ICP4 (red) viral and anti-GFAP (top left; green) glial or anti-MAP2 neuronal (top right; green) antibodies. The viral antigens were found only in the hippocampal neurons and not the glia. (B) Immunofluorescent image showing molecular reactivation after hyperthermia. After plating, cultures were subjected to 0, 1, or 3 h at 43°C in 5% CO₂; after 24 h, VP16 (green) viral protein was detected with a clear increase in signal strength over treatment time. DAPI staining was used to mark the nuclei of the cells.