Figure 7

Expression of IFN-α, IFN-β and type 1 interferon-inducible genes in lung and bone marrow during infection with different Mtb strains. (A) Combined expression of IFN-α 1,2,5,6,7 mRNA in lung homogenate did not show significant differences between groups. No expression could be detected in uninfected mice (N/A). (B) Expression of IFN-β mRNA in lung homogenate was higher in the lungs of H37Rv-infected mice compared to EAI-1627-infected mice at 3 dpi. Other differences did not reach significance. (C) Combined expression in the lungs of type 1 interferon-inducible genes Mx1 (black), IFI44 (light grey) and CCL2 (dark grey), represented in a type 1 interferon signature, showed the highest level in the Beijing-1585 group at 7 dpi and in the H37Rv group at 14 dpi. For individual expression levels see Fig. S6. (D) Expression of IFN-β in the bone marrow is higher in the H37Rv group compared to Beijing-1585 at 3 dpi. N = 6 mice per group per time point, *p < 0.05, **p < 0.01, ***p < 0.001 after Bonferroni correction. Two-way, repeated measure ANOVA followed by Bonferroni correction was used to calculate significance for C.