TABLE 1.
Virus strain | Origin of gene segmenta:
|
Viral titer inb:
|
L+E64/L ratioc | Rankd | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
L1 | L2 | L3 | M1 | M2 | M3 | S1 | S2 | S3 | S4 | E64-treated cells | Untreated cells | |||
Parental | ||||||||||||||
T1L | L | L | L | L | L | L | L | L | L | L | 4.18 × 105 | 2.20 × 107 | 0.0190 | |
D-EA1 | E | E | E | E | E | E | E | E | E | E | 2.70 × 107 | 9.91 × 107 | 0.273 | |
Reassortant | ||||||||||||||
1-31 | L | L | L | L | L | L | E | L | E | E | 4.80 × 106 | 1.20 × 107 | 0.400 | 1 |
1-6 | E | E | L | L | E | L | L | E | L | E | 1.05 × 106 | 8.28 × 106 | 0.127 | 2 |
35 | E | E | E | E | L | E | L | E | E | E | 2.55 × 106 | 2.20 × 107 | 0.116 | 3 |
1-57 | L | L | L | L | E | L | L | E | E | E | 1.35 × 106 | 1.21 × 107 | 0.112 | 4 |
1-29 | E | E | E | E | E | E | L | E | E | E | 1.17 × 106 | 1.40 × 107 | 0.0836 | 5 |
33 | E | E | E | L | E | E | L | E | E | E | 2.40 × 105 | 2.90 × 106 | 0.0828 | 6 |
1-25 | E | E | E | L | E | E | L | E | E | E | 1.32 × 106 | 1.90 × 107 | 0.0692 | 7 |
1-28 | E | E | L | E | E | E | E | E | L | E | 3.35 × 106 | 5.30 × 107 | 0.0632 | 8 |
29 | E | E | E | E | E | E | L | E | E | E | 6.85 × 105 | 1.19 × 107 | 0.0576 | 9 |
1-1 | E | E | E | E | E | E | L | E | L | E | 7.75 × 105 | 2.30 × 107 | 0.0337 | 10 |
1-11 | E | E | E | L | E | L | L | E | E | L | 4.53 × 105 | 1.75 × 107 | 0.0259 | 11 |
1-9 | E | E | E | L | E | L | L | E | E | L | 4.08 × 105 | 1.63 × 107 | 0.0251 | 12 |
1-56 | E | E | E | E | L | L | L | E | E | L | 2.25 × 104 | 1.05 × 106 | 0.0214 | 13 |
1-10 | L | L | L | L | L | E | L | L | E | L | 2.95 × 105 | 2.20 × 107 | 0.0134 | 14 |
47 | E | E | E | L | E | E | L | E | E | L | 3.15 × 104 | 2.85 × 106 | 0.0111 | 15 |
1-27 | E | E | E | E | E | E | L | E | E | L | 9.25 × 104 | 1.03 × 107 | 0.00902 | 16 |
1-30 | E | E | L | E | E | E | E | L | E | L | 4.00 × 105 | 5.40 × 107 | 0.00741 | 17 |
22 | L | E | L | E | E | E | L | E | E | L | 8.05 × 104 | 1.33 × 107 | 0.00608 | 18 |
1-44 | E | E | L | E | E | E | L | E | E | L | 3.80 × 104 | 1.23 × 107 | 0.00309 | 19 |
37 | E | E | E | L | E | E | E | E | E | L | 4.95 × 104 | 2.15 × 107 | 0.00230 | 20 |
Parental origin of each gene segment: L, gene segment derived from T1L; E, gene segment derived from D-EA1.
L cells (4 × 105) were infected with virus strains at an MOI of 2 PFU per cell. After a 1-h adsorption period, the inoculum was removed, fresh medium with or without 100 μM E64 was added, and cells were incubated at 37°C for 24 h. Cells were frozen and thawed twice, and viral titers in cell lysates were determined by plaque assay. The results are presented as mean viral titer at 24 h for two to four independent experiments for the reassortant viruses and six independent experiments for the parental viruses.
The mean viral titer at 24 h in E64-treated cells was divided by that in untreated cells to calculate an L+E64/L ratio for each virus strain.
Reassortant viruses are ranked from highest to lowest based on their L+E64/L ratios.