Table 2.
Inhibitory activity of L-742,001 and ribavirin against influenza viruses or reconstituted vRNPs carrying mutant forms of PAc
| Mutation in PA | Virus yield assay in MDCK cellsa |
vRNP reconstitution assay in HEK293T cells (EC50b) |
||||
|---|---|---|---|---|---|---|
| L-742,001 |
Ribavirin |
L-742,001 | Ribavirin | |||
| EC90 | EC99 | EC90 | EC99 | |||
| WT | 4.3 ± 0.8 | 6.6 ± 1.3 | 7.8 ± 0.6 | 11 ± 1 | 3.8 ± 1.5 | 9.7 ± 1.8 |
| T20A | 14 ± 1.9 (3) | 21 ± 4 (3) | 8.4 ± 1.2 (1) | 14 ± 3 (1) | 9.6 ± 1.2 (3) | 12 ± 4 (1) |
| Y24L | 6.1 ± 1.3 (1) | 14 ± 4 (2) | 13 ± 2 (2) | 28 ± 5 (2) | 3.7 ± 0.7 (1) | 13 ± 1 (1) |
| A37T | 4.8 ± 0.7 (1) | 7 ± 0.9 (1) | 7.6 ± 0.9 (1) | 11 ± 2 (1) | 5.7 ± 3 (1) | 9.3 ± 3.5 (1) |
| I38T | 4.8 ± 0.7 (1) | 7.7 ± 0.8 (1) | 8.2 ± 1.2 (1) | 12 ± 2 (1) | 8 ± 2.3 (2) | 9.2 ± 2.4 (1) |
| H41A | 14 ± 5 (3) | 28 ± 9 (4) | 12 ± 1 (2) | 19 ± 2 (2) | 77 ± 8 (20) | 10 ± 2 (1) |
| L42T | 9.1 ± 2.2 (2) | 15 ± 3 (2) | 8.6 ± 1.2 (1) | 12 ± 2 (1) | 13 ± 4 (3) | 7.6 ± 1.5 (1) |
| G81D | NV | NV | NV | NV | NV | NV |
| G81F | 49 ± 9 (12) | >90 ± 6 (>14) | 6.7 ± 0.5 (1) | 12 ± 1 (1) | 136 ± 45 (35) | 14 ± 6 (1) |
| G81K | NV | NV | NV | NV | NV | NV |
| G81T | >37 ± 6 (>9) | >81 ± 10 (>12) | 6.6 ± 1.2 (1) | 11 ± 2 (1) | 130 ± 35 (34) | 7.5 ± 2.1 (1) |
| G81V | >96 ± 4 (>22) | >100 ± 0 (>15) | 10 ± 1 (1) | 14 ± 1 (1) | NV | NV |
| R84L | 1.6 ± 0.3 (0.4) | 3.9 ± 0.8 (0.6) | 6.8 ± 0.7 (1) | 12 ± 2 (1) | 2.7 ± 0.8 (0.7) | 4.7 ± 0.3 (0.5) |
| W88L | 3.6 ± 0.5 (1) | 8.7 ± 1.1 (1) | 11 ± 1 (1) | 17 ± 2 (1) | 7.1 ± 0.2 (2) | 9.7 ± 1.7 (1) |
| F105L | 2 ± 0.3 (0.5) | 4.2 ± 0.8 (0.6) | 7.5 ± 0.8 (1) | 12 ± 2 (1) | 1.6 ± 0.4 (0.4) | 6.7 ± 0.8 (1) |
| L106T | 3.6 ± 1.1 (1) | 8.9 ± 1.5 (1) | 7 ± 0.3 (1) | 11 ± 1 (1) | 4.4 ± 1.1 (1) | 6.5 ± 2.3 (1) |
| I120D | NV | NV | NV | NV | NV | NV |
| I120F | NV | NV | NV | NV | NV | NV |
| I120K | NV | NV | NV | NV | NV | NV |
| I120T | >78 ± 9 (>18) | >100 ± 0 (>15) | 5.1 ± 0.5 (1) | 11 ± 2 (1) | 113 ± 29 (29) | 12 ± 3 (1) |
| I120V | 2.7 ± 0.6 (1) | 6.1 ± 1.6 (1) | 6.7 ± 1 (1) | 11 ± 1 (1) | 3 ± 0.9 (1) | 9.8 ± 0.8 (1) |
| V122T | 9.3 ± 1.2 (2) | 15 ± 2 (2) | 6.8 ± 0.5 (1) | 8.8 ± 1.2 (1) | 20 ± 9 (5) | 11 ± 3 (1) |
| R124E | NV | NV | NV | NV | NV | NV |
| R124Q | <1.3 ± 0.2 (0.3) | 3.2 ± 0.6 (0.5) | 6.9 ± 0.5 (1) | 12 ± 1 (1) | 1.3 ± 0.5 (0.3) | 7.1 ± 2.7 (1) |
| Y130A | <1.7 ± 0.3 (0.4) | 5.4 ± 0.5 (0.8) | 10 ± 0 (1) | >29 ± 4 (>3) | 1.3 ± 0.3 (0.3) | 6.7 ± 1.8 (1) |
| K134A | NV | NV | NV | NV | NV | NV |
Antiviral activity expressed as the compound concentrations (in μM) producing a 1-log10 (EC90) or 2-log10 (EC99) reduction in virus yield at 24 h p.i., as determined by real-time RT-PCR. Data in parentheses indicate fold increase compared to the WT.
EC50, 50% effective concentration (in μM), i.e., compound concentration producing 50% reduction in vRNP-driven firefly reporter signal, estimated at 24 h after transfection of HEK293T cells. Data in parentheses indicate fold increase compared to the WT.
NV, nonviable mutation, no virus recovered by reverse genetics, or vRNP activity in HEK293T cells of <2% relative to that of the WT. Data shown are means ± SEM from at least 3 independent tests.