Table 2.
Differential effects of type I IFNs on resistance to WEEV-induced cytopathology in immature and differentiated BE(2)-C human neuronal cells.
| IC50 (pg/ml)a | ||
|---|---|---|
| Type I IFNb | Immature | Differentiated |
| IFN-α1 (αD) | >1000 | >1000 |
| IFN-α2a (αA) | 812 ± 114 | 368 ± 77* |
| IFN-α4 (α4b) | >1000 | 623 ± 179 |
| IFN-α5 (αG) | 782 ± 86 | 964 ± 25 |
| IFN-α6 (αK) | 589 ± 119 | 649 ± 213 |
| IFN-α7 (αJ1) | >1000 | 910 ± 81 |
| IFN-α8 (αB2) | 151 ± 5 | 57 ± 28* |
| IFN-α10 (αC) | 230 ± 36 | 116 ± 36 |
| IFN-α14 (αH2) | 830 ± 31 | 344 ± 79* |
| IFN-α16 (αWA) | 732 ± 67 | 239 ± 66* |
| IFN-α17 (αI) | 639 ± 209 | 428 ± 144 |
| IFN-α21 (αAF) | 912 ± 51 | 789 ± 211 |
| IFN-β | 349 ± 85 | 177 ± 24 |
| IFN-ω | >1000 | 210 ± 125 |
Values represent weight-based concentrations that inhibited WEEV-induced cytopathology by 50% at 48 and 72 hpi for immature and differentiated BE(2)-C cells, respectively. Results represent the mean ± SEM from three independent experiments. Specific activities listed by the manufacturer as determined by antiviral effects against vesicular stomatitis virus in Madin-Darby bovine kidney cells (IFNα subtypes), vesicular stomatitis virus in Vero cells (IFNβ), or encephalomyocarditis virus in A549 cells (IFNω), were between 1 to 4 × 108 U/mg for all type I IFNs except IFN-α1 (7.5 × 107 U/mg) and IFN-α21 (6.3 × 108 U/mg). Similar differences between immature and differentiated BE(2)-C cells were obtained when we used specific activity measurements to calculate IC50 values with IFNα subtypes.
Alternative IFNα subtype designations are given in parentheses. All type I IFNs were purified recombinant proteins produced in E. coli except IFN-β, which was produced in mammalian cells.
p < 0.05 compared to immature cells. Indeterminate values above the range of the assay (>1000 pg/ml) were not subjected to statistical analyses.