TABLE 4.
Pulmonary virus titer on day 4 in cotton rats administered placebo or PAMPS at different intervals after experimental inoculation of the animals with MVa
| Expt no. and group | Challenge virus | Treatment | Dose (mg/kg) | Time of dosing | Virus titer (log10/g lung) in cotton rat no.:
|
Mean ± SD titer | |||
|---|---|---|---|---|---|---|---|---|---|
| CR1 | CR2 | CR3 | CR4 | ||||||
| Expt 1 | |||||||||
| 1 | MV | Placebo | 0 | +5 min | 4.0 | 4.5 | 4.1 | 3.5 | 4.1 ± 0.3 |
| 2 | MV | PAMPS | 100 | +5 min | 0 | 0 | 3.0 | 0 | 0.8 ± 1.5b |
| 3 | RSV | PAMPS | 100 | +5 min | 0 | 0 | 0 | 0 | 0 ± 0b |
| 4 | MV | Placebo | 0 | +60 min | 4.0 | 5.0 | 4.0 | 4.0 | 4.3 ± 0.5 |
| 5 | MV | PAMPS | 100 | +60 min | 4.0 | 4.1 | 4.0 | 4.5 | 4.1 ± 0.3 |
| Expt 2 | |||||||||
| 1 | MV | Placebo | 0 | Days 0–3 | 5.0 | 4.5 | 4.5 | 5.1 | 4.0 ± 0.4 |
| 2 | MV | PAMPS | 100 | Day 0 | 3.0 | 3.5 | 3.5 | 3.6 | 3.3 ± 0.3b |
| 3 | MV | PAMPS | 100 | Days 1–3 | 4.0 | 4.5 | 4.6 | 4.0 | 4.3 ± 0.3 |
| 4 | MV | PAMPS | 100 | Days 0–3 | 3.1 | 3.0 | 3.5 | 3.0 | 3.1 ± 0.3b |
All of the cotton rats used in these experiments were inoculated i.n. on day 0 with 104 median CCID50s of MV or RSV. In experiment 1, the animals in groups 1 to 3 were inoculated i.n. with either placebo (distilled water) or PAMPS 5 min after virus inoculation, while those in groups 4 and 5 were inoculated with PAMPS 55 min later. In experiment 2, the animals were inoculated i.n. with PAMPS on the indicated days, with all of the inoculations on day 0 being given 30 min after virus inoculation. All of the cotton rats were sacrificed on day 4 after virus inoculation, at which times their lungs were removed and tested for virus.
Boldfaced means and standard deviations indicate statistical significance between means of these groups and the placebo control (P ≤ 0.05) as determined by the Kruskal-Wallis nonparametric analysis of variance test; number of animals per group was 4.