FIG. 3.
Quantification of IFN-γ levels in spleens of mice infected with B. abortus 2308 or the virB mutant. (A) Transcript levels in spleens from groups of five mice infected with either B. abortus 2308 (black bars) or the virB mutant (white bars) were assayed by real-time reverse transcription-PCR at different times postinoculation. Increases (2−ΔΔCT) in transcript levels were calculated by normalizing CT values for IFN-γ levels to CT values for GAPDH levels and to CT values for IFN-γ levels measured in a group of mock-infected mice. (B) Cytokine measurement of IFN-γ in splenic tissue by Multi-Plex assay was performed with groups of five mice infected with either B. abortus 2308 or the virB mutant at different times postinoculation. Data shown are increases in cytokine concentrations over preinfection levels. The significance of differences for wild-type and mutant mice at each time point was determined using a paired Student's t test. Error bars represent standard deviations. Asterisks indicate significant differences between the wild type and the mutant (P < 0.05). Results shown at the top and bottom are from two independent experiments.