Table 4.

Contribution of cp45 mutations to the att  phenotype

ViruscNo. of hamstersMean virus titera(log10 TCID50/g ± SE) in:Reduction in titerb in:
Nasal turbinatesLungsNasal turbinatesLungs
cp4554.9 ± 0.41.9 ± 0.21.94.1
r cp4595.0 ± 0.12.5 ± 0.01.83.5
r cp45 L54.2 ± 0.12.1 ± 0.32.63.9
r cp45 3′NL54.7 ± 0.22.1 ± 0.32.13.9
r cp45 F54.6 ± 0.23.4 ± 0.62.22.6
r cp45 C54.8 ± 0.33.1 ± 0.72.02.9
r cp45 3′NCMFHN105.7 ± 0.23.9 ± 0.61.12.1
r cp45 HN6.3 ± 0.25.3 ± 1.00.50.7
r cp45 M56.6 ± 0.15.4 ± 0.60.20.6
r cp45 3′N156.7 ± 0.15.9 ± 0.50.10.1
rPIV3 wt106.8 ± 0.16.0 ± 0.3
  • a Groups of 5 to 15 hamsters intranasally received 106.0 TCID50 of virus per animal in a 0.1-ml inoculum, and lungs and nasal tubinates were harvested 4 days later. The TCID50 for each sample was determined on LLC-MK2 cells at 32°C. Values are means for the indicated number of hamsters from one or two separate studies.

  • b Compared to rPIV3 wt.

  • c cp45 is a biologically derived virus, and the others are recombinants.