FIG 7.

MsbA contributes to downmodulating the inflammatory response after A. fumigatus infection. (A) msbA mRNA expression during infection. A. fumigatus cells were harvested from lungs of infected animals after 4 h and 12 h (PI, postinfection). mRNA was extracted for qRT-PCR assay. Data are presented as mean ± SEM (n = 3 to 4 mice per group). *, significantly different (P < 0.05). (B) Lethality of mice infected with wild-type or ΔmsbA strain. Mice were infected intranasally with 40 μl of suspension containing 1 × 10⁸ conidia of wild-type or ΔmsbA strain, and mortality was monitored for 7 days. NI, noninfected. (C to G) Inflammatory infiltrate was analyzed in BALF of infected animals. Infection with ΔmsbA strain altered inflammatory cells recruitment into airways. Intranasally infected mice had BALFs harvested at day 1 postinfection for inflammatory cell infiltrate determination. Total cell (C), macrophage (D), neutrophil (E), lymphocyte (F), and eosinophil (G) absolute counts in BALF. Data are presented as mean ± SEM (n = 5 to 8 mice per group). *, significantly different (P < 0.05) compared to wild-type-infected group. #, significantly different (P < 0.05) compared to noninfected group. (H) In vitro phagocytosis was performed with RAW 264.7 immortalized macrophages challenged with wild-type or ΔmsbA strain for 2 h and 4 h for phagocytosis. The relationship between the number of macrophages containing conidia inside and the total number of macrophages was used to calculate phagocytic index. One hundred macrophages were counted for each coverslip. (I) Fungal survival was quantified as CFU/phagocytic index (PI). ΔmsbA conidium number after 6 h of phagocytosis was higher. *, significantly different (P < 0.05) compared to wild type.