Herpes Simplex Virus 2 ICP0− Mutant Viruses Are Avirulent and Immunogenic: Implications for a Genital Herpes Vaccine
Titers of (A) wild-type HSV-2 MS, (B) HSV-2 0Δ104, (C) HSV-2 0ΔRING, (D) HSV-2 0Δ254, (E) HSV-2 0Δ810, or (F) HSV-2 0ΔNLS at times after inoculating ICP0+ L7 cells, Vero cells, or interferon-β-treated Vero cells with 0.1 pfu per cell. At each indicated time point, cultures were transferred from 37°C to −80°C, and titers of infectious virus were determined upon thawing by a microtiter plaque assay. The mean ± sd of viral titer at each time point (n = 2 per data point) is plotted as a function of time. Arrows on the right of each graph represent the antilogarithm (10x) of the difference at 48 hours p.i. between viral titer in ICP0+ L7 cells versus interferon-β-treated Vero cells. Each graph is a representative result from 2 to 3 independent experiments.