Table 5.

T-cell response of IFN-γ−/− mice immunized with plasmid NPV1 and challenged with the PR8 virus

StrainPulmonary virus titeraCytotoxic activitybCytokine productionc
SplenocytesBAL cells
IFN-γIL-4IL-2IFN-γIL-4IL-2
BALB/c024 ± 2155 ± 216 ± 342 ± 1227 ± 78 ± 334 ± 10
IFN-γ−/−1.7 ± 1.529 ± 3012 ± 460 ± 506 ± 536 ± 5
  • a Pulmonary virus titers were measured 7 days after infection and the results are expressed as geometric means for groups of three mice ± SE. A value of 0 was given to nondetectable virus titers.

  • b The CTL activity of splenocytes against PR8-infected target cells was estimated after in vitro stimulation with virus-infected APC at a responder/stimulator ratio of 1:1. The results were expressed as mean percent specific lysis of triplicates ± SE.

  • c Cells harvested from spleens or bronchoalveolar tracts were restimulated in vitro with APC pulsed with the PR8 virus. The concentration of cytokines was estimated by ELISA. The results are expressed as means of duplicates ± SE (picograms per milliliter).