FIG. 7.

Spm8CHAS primarily targets the HSV viral particle and blocks multiple steps in viral infection. Spm8CHAS was preincubated with ≈10⁴ PFU of HSV-2(G) per ml an for 1 hour at 37°C, then diluted 50-fold to yield ≈200 PFU/well on control plates, and inoculated onto monolayers of CaSki cells in duplicate in 12-well dishes. As a control, Spm8CHAS was exposed to virus and then immediately diluted 50-fold and inoculated onto cells, with no preincubation period. Alternatively, cells were preincubated with the indicated concentrations of drug for 1 h at 37°C and then either washed extensively or not washed prior to inoculation with HSV-2(G). Results are presented as PFU/well as a percentage of PFU formed in the presence of medium alone and are means ± standard deviations (SD) obtained from three experiments conducted in duplicate (A). Synchronized infection assays were also conducted, and Spm8CHAS (5, 10, or 50 μg/ml), heparin (100 μg/ml), or acyclovir (50 mg/ml) was added at the time of binding (for 4 h at 4°C), entry (for 30 min at the time of temperature shift to 37°C), or immediately postentry (after citrate treatment) for the remaining duration of the experiment period. Plaques were counted at 48 h, and results are presented as PFU/well as a percentage of PFU formed in the presence of medium alone and are means ± SD obtained from three experiments conducted in duplicate (B).