Fig. 8

M2b-polarized macrophages produce high levels of IL-10 and impair IFN-ɣ expression in CD4⁺ naïve T lymphocytes. a IL-10 gene expression was proven in macrophages isolated from wild type macrophages (M2) after co-culture with preconditioned MSCs and IL-4 or treatment with recombinant IL-4 (20 mg/ml) + IL-6 (25 ng/ml), respectively. Expression of IL-10 in cells from IL-6Rα-deficient mice (IL6R-KO M2) after co-culture with preconditioned MSCs + IL-4 was additionally analyzed. Fold change in gene expression vs. control cells is depicted. n = 6, *p < 0.05; ***p < 0.001. b Wild type macrophages pre-cultured with or without preconditioned MSCs and IL-4 for 24 h were further co-cultured with CD4⁺ naïve T lymphocytes allowing direct cell-cell interactions for further 24 h. Gene expression of Th1 markers GATA-3 and IFN-ɣ as well as IL-2 and IL-4 (Th2) was analyzed by real-time PCR. n = 5, *p < 0.05. IL interleukin, IFN-ɣ interferon gamma, M macrophage, T lymphocyte