Fig. 3

IL-13 Mφs maintain their IL-13 secretion and anti-inflammatory markers upon LPS stimulation. a–f Mφs were isolated from C57BL/6J mice. M0, M2, and IL-13 Mφs were left unstimulated (control) or were stimulated with LPS for 24 h. a IL-13 secretion, determined by ELISA, was not changed following LPS stimulation in IL-13 Mφs. Data represent mean ± SEM. n = 5–6. b, c Gene expression, determined by qPCR, showed that LPS exposure significantly increased Arg1 (b) and iNOS (c) expression by IL-13 Mφs compared to their untreated control. Data were normalized to M0 Mφs and represent mean ± SEM. n = 8–9. d, e Quantification of the western blot analysis showed that the protein expression of Arg1 (d) and iNOS (e) were not altered by LPS stimulation in IL-13 Mφs. Data were normalized to M0 Mφs and represent mean ± SEM. n = 4–6. f Using a Griess assay, NO was measured in the medium. Although NO secretion was significantly increased in the LPS-stimulated IL-13 Mφs compared to their untreated control, the secretion was significantly reduced compared to the M2 Mφs stimulated with LPS. Data represent mean ± SEM. n = 9. Kruskal–Wallis test with Dunn’s correction. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001