Table 1.
ICP27 causes the secretion of a heat-stable protease-sensitive IFN antagonist that is 10 – 50 kDa.
| Medium from cells transfecte d with | Treatment | IFN | % Cells with StatI Localization in* | ||
|---|---|---|---|---|---|
| Nucleus | Cytoplasm | Both | |||
| Empty vector | None | − + |
7±1 81±5 |
69±6 3±2 |
24±5 16±4 |
| ICP27 vector | − + |
1±1 37±19, p<0.05+ |
81±2 40±15 |
18±3 21±4 |
|
| Empty vector | 55°C 1 hour, 95°C | − + |
0.5±0.5 75±4 |
68±4 1±1 |
32±3 24±2 |
| ICP27 vector | 10 min | − + |
2±2 41±3, p<0.01+ |
75±6 18±3 |
21±5 41±0.5 |
| Empty vector | 55°C 1 hour, 95°C 10 min with proteinase K | − + |
0.5±0.5 58±7 |
82±2 9±0.5 |
18±2 32±7 |
| ICP27 vector | − + |
0.5±0.5 72±1, p>0.05 |
79±1 2±0.5 |
20±1 26±1 |
|
| Empty vector | Filtered through 50 kDa pores | − + |
1±0.5 84±2 |
70±4 0.5±0.5 |
29±5 16±2 |
| ICP27 vector | − + |
2±1 59±3, p<0.05+ |
69±3 2±0.5 |
28±3 39±3 |
|
| Empty vector | Filtered through 10 kDa pores | − + |
3±1 74±14 |
70±3 4±5 |
31±2 22±6 |
| ICP27 vector | − + |
3±1 77±4, p>0.25 |
67±2 2±0.5 |
31±3 20±4 |
|
*
Vero cells were transfected with empty vector (pCI) or an ICP27 expression vector (pCI-ICP27). At 24 hours post-transfection, medium from each culture was harvested and left untreated, heated to 55°C for 60 min and to 95°C for 10 min in the absence or presence of proteinase K, or passed through a 50- or 10-kDa filter before being transferred to naïve Vero cells. At 24 hours after media transfer, these cells were treated with IFNα at 104 U/mL for 30 min, as indicated, fixed, and stained for Stat-1. The distribution of Stat-1 localization was determined as in Figure 1.
+
compared with control medium from cells transfected with empty vector.