A time-related study of Brefeldin A effects in HSV-1 infected cultured human fibroblasts

Glycoprotein D (gD-1) is an essential virion envelope component of herpes simplex virus type 1 (HSV-1) normally transported to the plasma membrane of the infected cells. In the present study, the intracellular transport of gD-1 was inhibited in cultured HSV-1 infected human fibroblasts by Brefeldin A (BFA) 1 microgram/ml medium added for 12 h after virus adsorption. Immunofluorescence light- and confocal microscopy revealed abolished transport of gD-1 to the plasma membrane, juxtanuclear accumulation of gD-1, and a disorderly arrangement of the tubulin fibres. Withdrawal of BFA influence for more than 60 min resulted in incomplete transport but increasing accumulation of gD-1 in the plasma membrane and in Golgi-like areas close to the nuclei. The tubulin pattern was almost normalized 6 h after removal of BFA. The egress of infectious HSV-1 particles released 9 h post-BFA treatment was not fully reestablished. The results indicate that BFA effects were not completely reversible and caused a sort of cytotoxic influence involving the structure of tubulin.