Characterization of macrophages after M1 or M2 polarization. After stimulation with LPS/IFNG, M1 macrophages showed a dendritic morphology while IL4/IL13 (M2) stimulated and unstimulated macrophages showed a rounded and/or spindle-shaped morphology (A). The three primary macrophages subsets showed, compared to reference gene YWHAZ, a high expression of CD68. In M1 polarized macrophages the CD68 gene expression is downregulated while the expression of CD14 is upregulated compared to M2 or unstimulated macrophages (B). LPS/IFNG-stimulated (M1) macrophages showed upregulated gene expression of IL1B, IL6, CCL2 and CD40 (C). IL4/IL13-stimulated (M2) macrophages upregulated the gene expression of CLEC10A, MRC1 and tended to upregulate CCL18. IL1R2 showed a high expression in M2 and unstimulated macrophages and was downregulated in M1 polarized macrophages (D). At protein level, more CCL2 was observed in conditioned medium from M1 macrophages. CCL18 protein secretion showed, like CCL2, values that correlated with gene expression (E). * p < 0.05, Difference between LPS/IFNG and IL4/IL13 stimulated macrophages, ** p < 0.01, *** p < 0.001. # p < 0.05, Difference between LPS/IFNG stimulated and unstimulated macrophages, ### p < 0.001. ^^ p < 0.01, Difference between IL4/IL13 stimulated and unstimulated macrophages. Data were analyzed using one-way ANOVA followed by Tukey’s post-test. Gene expression analysis n = 4, protein secretion n = 3.