Human foreskin fibroblast cells (HFF) were seeded at 1.5610 6 in a 175 2 cm flask and grown to 90% confluence then growtharrested in medium supplemented with only 100 U/ml Penicillin-G and 100 mg/ml Streptomycin for five days. Real-time PCR experiments were conducted with growth-arrested HFFs that were inoculated in triplicate with 1000 particles/cell of entry-defective HSV-1 in warm, serum-free medium, with parallel mock-infected cells that received an equivalent volume of PBS in warm serumfree medium. Inoculations took place at 37uC. At the indicated times after the addition of virus, the medium was removed, the cells were lysed with TRI Reagent (Sigma) and total RNA was immediately purified. For each entry-defective HSV-1 mutant, three independent biological replicates were carried out. Microarray experiments were conducted under the same conditions using wild-type HSV-1 (SC16) at an MOI of 20.