FIG 4.
Effect of the simultaneous absence of TLR7, TLR9, or TLR13 on neutrophil recruitment and cytokine production in the lung during pneumococcal infection. Kinetics of bacterial burden (A), neutrophil counts (C), and cytokine concentrations (B and D to H) in lung homogenates after i.n. challenge with S. pneumoniae (5.5 × 107 CFU/mouse). Lung homogenates were collected at different times after infection (1, 3, 7, 24, and 48 h). The dashed lines indicate the limit of detection of the test. Shown are cumulative data from two experiments, each involving 4 animals per group. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 versus WT mice, determined by Wilcoxon test (A) and Student’s t test (B to H); ns, not significant.