TABLE 1.
Effects of IFN-α and cell type on plaque formation efficiency of different virusesa
| Virus (strain) | Gene inactivated | −IFN-α/+IFN-α ratio
|
|
|---|---|---|---|
| Vero cells | U2OS cells | ||
| KOS | 5.5 | 3.9 | |
| 4 | 4.6 | ||
| 5.8 | 4.8 | ||
| 6.2 | |||
| 17syn+ | 7 | 2.2 | |
| 2.5 | 1.9 | ||
| 2.4 | |||
| 2.0 | |||
| n212 (KOS) | ICP0 | 230 | 10.9 |
| 207 | 10 | ||
| 285 | 8.5 | ||
| 260 | |||
| dlX3.1 (KOS) | ICP0 | 1,550 | 4.4 |
| >1,200 | 5.1 | ||
| 7134 (KOS) | ICP0 | 300 | 1.6 |
| >200 | |||
| dl1403 (17syn+) | ICP0 | 320 | 3 |
| 200 | |||
| in1814 (17syn+) | VP16 | 14 | 2.9 |
| 22 | 3.8 | ||
| 10.9 | |||
| V422 (KOS) | VP16 | 16 | 10 |
| 45 | 28 | ||
| d13lacZ (KOS) | UL13 | 4 | 5.4 |
| d22lacZ (KOS) | ICP22 | 5 | 10 |
| ΔSma (KOS) | vhs | 5.8 | 4.4 |
| VSV | >20,000 | 6.7 | |
a
Vero and U2OS cells were mock treated or pretreated for 16 h with 1,000 U of human lymphoblastoid IFN-α (Sigma) per ml prior to infection. Results from individual experiments are reported for each virus in each cell line, with the ratio determined by dividing the viral titer in the absence versus presence of IFN-α pretreatment. The symbol > indicates that no plaques were visible at the lowest dilution of virus tested in the presence of IFN-α, and thus the exact level of inhibition is unknown in that experiment.