Fig 6.
Murine cytokine/chemokine production in response to infection with high-dose ACT- and FHA-deficient bacteria. BALB/c mice were intranasally inoculated with 50 μl of PBS containing 5.5 × 105, 1 × 106, or 1 × 107 CFU of the ΔcyaA ΔfhaB strain (RB516) and 5.5 × 105 CFU from the ΔfhaB strain (RBX9). (A) Bacterial burden. Each point represents the number (log10) of CFU recovered from the right lungs of a single animal, and the data are from two independent experiments. (B) Levels of TNF-α, IL-1β, IL-6, IL-17, KC, MIP-1α, MIP-2, and MCP-1 were measured at 3 h, 48 h, and 72 h p.i. in lung homogenates of mice inoculated with 5.5 × 105 CFU of the ΔfhaB strain or the ΔfhaB ΔcyaA strain or 1 × 107 of the ΔfhaB ΔcyaA strain. Cytokines were assayed using Luminex technology and standardized to a range of 3.2 to 22,000 pg/ml, depending on the analyte assayed. Dashed gray lines represent the upper limit of detection. The cytokine profile of animals infected with the intermediate dose of 1 × 106 is not shown. Statistics are calculated as significant variation from the ΔfhaB strain (*, P < 0.05; **, P < 0.001; ***, P < 0.0001).