Table 1.
Replication efficiency of influenza viruses in ex vivo infected human lung tissues
| NP vRNA copy number a |
NP positive %b |
|||||
|---|---|---|---|---|---|---|
| Sample ID | CA/04 | ST/92 | VNM/1194 | CA/04 | ST/92 | VNM/1194 |
| 1 | 118.40 | 21.03 | 867.73 | 60 (6/10) | 20 (2/10) | 90 (9/10) |
| 2 | 184.40 | 38.38 | 15038.93 | 89 (8/9) | 20 (2/10) | 100 (9/9) |
| 3 | 21.19 | 11.57 | 200.53 | 37.5 (3/8) | 0 (0/9) | 89 (8/9) |
| 4 | 26.46 | 10.78 | 10390.36 | 11.1 (1/9) | 20 (1/5) | 70 (7/10) |
| 5 | 236.42 | 11.91 | 2731.48 | 87.5 (7/8) | 33.3 (3/9) | 100 (9/9) |
| 6 | 322.93 | 15.98 | 4609.89 | 60 (6/10) | 38.5 (5/13) | 100 (11/11) |
| 7 | 362.03 | 34.86 | 1032.13 | 33.3 (2/6) | 14.3 (1/7) | 14.3 (1/7) |
| 8 | 276.58 | 12.73 | ND | 100 (4/4) | 66.7 (2/3) | ND |
| 9 | 1246.17 | 20.20 | 9116.28 | 57.1 (4/7) | 20 (2/10) | 85.7 (6/7) |
| 10 | 476.69 | 31.46 | 4252.72 | 60 (6/10) | 33.3 (2/6) | 100 (6/6) |
| 11 | 78.23 | 26.84 | 1712.99 | 50 (3/6) | 0 (0/7) | 100 (10/10) |
| 12 | 655.21 | 29.81 | ND | 11.1 (1/9) | 0 (0/6) | ND |
| 13 | 1696.51 | 22.98 | ND | 25 (3/12) | 25 (3/12) | ND |
|
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| P value | 0.011 | 0.017 | ||||
For each of the three tested viruses, lung tissues were inoculated with 106 TCID50 virus, and incubated at 37°C with 5% CO2 for 1 hour and then incubated for a further 48 hours in serum free F12K Nutrient Mixture (GIBCO, New York, USA) supplemented with 0.5μg/ml TPCK-trypsin. Replication efficiency of influenza viruses in 13 different ex vivo infected human lung tissues was assessed by quantitative RT-PCR and immunostaining to determine vRNA copy number and the frequency of NP positive cells, respectively.
NP gene copy numbers per 1000 copies of beta-actin gene as detected by real time RT-PCR.
number of tissue cubes with NP positive staining (at least one positive cell)/number of tissue cubes examined.
ND: not done.
P value for comparison of vRNA copy number between CA/04 and ST/92 is 0.011, and between CA/04 and VNM/1194 is 0.017.