A Mutation in IL4RA Is Associated with the Degree of Pathology in Human TB Patients

Figure 4

In the absence of the IL-4Rα alternative macrophage activation is obliterated in Mtb-infected mice. BALB/c (white circles), (black circles), and IL-4Rα^−/− (black rhombs) mice were infected with 100 CFU Mtb H37Rv per aerosol. At different time points, gene expression of (a) fizz1, (b) ym1, (c) arg1, and (d) arginase activity in lung homogenates of infected mice was determined. Results represent means and standard deviations of 4-5 mice ( for comparison of and BALB/c mice; for comparison of and IL-4Rα^−/− mice; nonparametric ANOVA with Dunn’s Multiple Comparison Test). One experiment representative of two performed is shown. (e) For immunohistological detection of Arg-1, lung sections were prepared from mice at 113 days after infection (-5). Arg-1 expression was not found in the lungs of Mtb-infected BALB/c mice but was prominent in granulomas of mice surrounding the necrotic center. Deletion of the IL-4Rα abolished Arg-1 expression in lungs of mice. Representative photomicrographs of one experiment out of two performed are shown.

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