TABLE 1.
Complementation of HSV-1 viruses with mutations in ICP0, ICP4, OBP, or VP16 by adenovirus expression vectors
| Complementing vector | No. of plaques produced bya:
|
||||
|---|---|---|---|---|---|
| KOS | 7134 | n12 | hr94 | RP5 | |
| Controls | |||||
| None (Vero cells) | 128 ± 2 | 1 ± 0 | 0 ± 0 | 0 ± 0 | 3 ± 1 |
| None (complementing cells)b | 62 ± 6∗ | 114 ± 6∗ | 104 ± 5∗ | 148 ± 5∗ | |
| Test vectorsc | |||||
| Ad.T-ICP0 | 110 ± 2 | 90 ± 5∗ | 0 ± 0 | 0 ± 0 | 186 ± 8∗ |
| Ad.T-n212 | 122 ± 10 | 1 ± 1 | 0 ± 0 | 0 ± 0 | 9 ± 1 |
| Ad.T-ICP4 | 66 ± 11 | 1 ± 1 | 115 ± 7∗ | 0 ± 0 | 22 ± 1 |
| Ad.T-OBP | 99 ± 7 | 1 ± 0 | 0 ± 0 | 454 ± 14∗ | 8 ± 0 |
| Ad.T-OBPΨ | 97 ± 8 | 1 ± 1 | 0 ± 0 | 0 ± 0 | 6 ± 1 |
| Ad.T-VP16 | 111 ± 2 | 0 ± 0 | 0 ± 0 | 0 ± 0 | 108 ± 6∗ |
| Ad.T-VP16Δ | 57 ± 1 | 0 ± 0 | 0 ± 0 | 0 ± 0 | 6 ± 1 |
| Ad.C-rtTA only | 112 ± 12 | 0 ± 0 | 0 ± 0 | 0 ± 0 | 4 ± 1 |
Vero cells in six-well plates were infected with 100 to 200 PFU of wild-type HSV-1 strain KOS or KOS-derived mutant 7134 (ICP0−), n12 (ICP4−), hr94 (OBP−), or RP5 (VP16−). Mean numbers of HSV plaques (± standard deviations) observed on untreated Vero cells (n = 2 per group), on complementing cells (n = 3 per group), or on Vero cells superinfected with one of eight adenovirus vectors (n = 2 per group) are given. The values for primary tests in which HSV-1 mutants were complemented with adenovirus vectors that provided the missing gene products in trans are shown in boldface type. Values with asterisks represent a more than 30-fold increase in the number of plaques formed on Vero cells relative to no-vector controls.
Mutant viral inocula were plated on the following complementing cell lines: 7134, on L7 cells; n12, on E5 cells; hr94, on 2B.11 cells; and RP5, on E5 cells treated with 5 mM HMBA.
Vero cells were coinfected with 10 PFU of Ad.C-rtTA/cell and 10 PFU of the indicated TRE adenovirus vector/cell and were overlaid with complete DMEM containing 1% methyl cellulose and 3 μM DOX.