Figure 2. Type II-activated macrophages produce IL-4.

(a) IFN-γ-primed BMMφ (10⁵/well) from WT and IL-4Rα-deficient mice were stimulated with LPS (10 ng/ml) in the presence or absence of opsonized SRBC (IC) for 24 hours. Cytokine production was measured in culture supernatants by ELISA. Shown are the means and SEM of triplicate wells from 1 of 3 experiments. *p<0.05 compared to medium and **p<0.001 compared to medium or IC. (b–d) IFN-γ-primed BMMφ (10⁵/well) from heterozygous G4 mice were stimulated with LPS (10 ng/ml) in the presence or absence of opsonized SRBC (IC) for 24 hours. IL-4 production by F4/80+ macrophages was assessed by flow cytometry (b). ELISA (c), or by fluorescence microscopy (d). IL-4-GFP is found intracellularly after LPS + IC (2 examples shown) but not LPS stimulation in DAPI-counterstained macrophages. Shown are the means and SEM from 3 experiments (b) or representative data from 1 of 3 experiments (c and d). *p<0.05 compared to t = 0 and **p<0.01 compared to medium by Dunnett’s Multiple Comparison Test.