FIG. 5.

Effect of virus glycosylation on TNF-α induction. (A and B) Confluent Vero cells were infected with increasing amounts of HSV-2 (1 × 10¹, 3 × 10², 1 × 10⁴, and 3 × 10⁵ PFU) in the presence and absence of 50 mM d-mannose (A) or N-acetylglucosamine (B). (C) HSV-2 was treated with 1,000 U of PNGase or PBS at 37°C for 3 h prior to infection in the same doses as above. After 48 h of infection, the cells were stained and plaques were counted. (D to F) RAW 264.7 cells were treated with 100 IU of IFN-γ per ml and 3 × 10⁵ PFU (multiplicity of infection, 0.6) of HSV-2 per ml. The growth medium was supplemented with free sugars (50 mM d-mannose [D] or N-acetylglucosamine [E]) or the virus was deglycosylated with PNGase prior to infection (F). After 8 h of infection, supernatants were harvested and analyzed for TNF-α bioactivity. Results are shown as means of duplicate cultures ± standard errors of the means. Similar results were obtained in three independent experiments. ∗, P < 0.05.