IL-6 regulates maturation of bone marrow-derived macrophages.

(A) BMDM from Il6rafl/fl×LysMcre and Il6rafl/fl control mice were differentiated with IL-4 or LPS + IFNγ and stimulated overnight with IL-6. Surface expression of CD38, IL-4Rα and MMR1 was analyzed by flow cytometry. Histograms and MFI-values are shown. (B) BMDM were stimulated as described before. Heat-killed listeria were added for the final 18 hours. NO2- concentration in supernatants was determined in duplicates. (C) BMDM were infected in vitro with listeria (Strain EGD, MOI 10 1), extracellular bacteria were removed with gentamicin and titers were determined at indicated time points. One representative experiment of two is shown. Bars in (B) represent mean ± SEM and circles in (C) median ± range. Significance was determined with (B) student’s t-test or (C) Mann-Whitney U test.