Table 3.
Viral Load In Brain and Spinal Cord of Perforin-Competent and -Deficient Mice
| Tissue | dpi* | Strain | VP2 copy # | Statistics^ |
|---|---|---|---|---|
| Brain | 7 | PFP+/+ PFP−/− |
6.6 ± 1.6 7.3 ± 1.1 |
p = 0.576 |
| 21 | PFP+/+ PFP−/− |
2.1 ± 2.1 5.7 ± 0.6 |
p = 0.035 | |
| 45 | PFP+/+ PFP−/− |
0.6 ± 1.3 1.5 ± 3.0 |
p = 0.620 | |
| 90 | PFP+/+ PFP−/− |
0.8 ± 1.4 0.8 ± 1.6 |
p = 0.978 | |
| 180 | PFP+/+ PFP−/− |
0.6 ± 1.5 1.7 ± 1.8 |
p = 0.334 | |
| Spinal Cord | 7 | PFP+/+ PFP−/− |
5.7 ± 0.2 5.4 ± 0.5 |
p = 0.382 |
| 21 | PFP+/+ PFP−/− |
5.2 ± 0.9 5.9 ± 0.5 |
p = 0.281 | |
| 45 | PFP+/+ PFP−/− |
5.8 ± 0.2 5.1 ± 1.2 |
p = 0.301 | |
| 90 | PFP+/+ PFP−/− |
5.6 ± 0.8 4.8 ± 0.3 |
p = 0.131 | |
| 180 | PFP+/+ PFP−/− |
4.4 ± 1.3 5.4 ± 1.8 |
p = 0.444 |
Days post-infection
post-ANOVA pair-wise analysis
Viral RNA expression was analyzed at the indicated days post-infection in the brain and spinal cord of PFP+/+ and PFP−/− mice. Values are reported as mean log10 copy number ± 95% CI for 3 animals per group. The detection threshold for this assay is 0.61 ± 0.58 log10 copies, as measured in uninfected brain and spinal cord samples. The early difference in viral load observed in the brain (21 dpi) is compatible with delayed viral clearance associated with the lack of perforin effector function. Based on this difference two-way ANOVA identified a weak strain dependence on viral load in the brain (p = 0.048). By 45 dpi the virus was essentially cleared from the brain. In the spinal cord, there were no differences between the groups. Two-way ANOVA revealed no effect of strain on viral load in the spinal cord (p = 0.882). Levels of expression of control GAPDH RNA were not different between the groups at any time point.