Fig. 1

NK-4 polarizes THP-1 macrophages toward an M1-like phenotype based on morphology and cytokine production. THP-1 macrophages were cultured with various concentrations of NK-4 and/or with 20 ng/ml IL-4/IL-13 for 2–3 days. Morphological features were assessed by light microscopy (a). Levels of TNF-α at day 3 were measured in culture supernatants by ELISA (b). Cell numbers at day 3 were determined by cell counting kit-8 (c). 3 days post-NK-4 treatment, cells were stimulated with 1 μg/ml LPS for 2 days. Levels of TNF-α (d) and IL-10 (e) were measured in the culture supernatants by ELISA. THP-1 macrophages were stimulated with various concentrations of LPS (f), Pam3CSK4 (g), or poly(I:C) (h) in the presence or absence of 4 μM NK-4 for 1–3 days. Levels of TNF-α in the culture supernatants on day 1 (f, g) and day 3 (h) were determined by ELISA. Graphs show the mean ± S.D. of triplicate cultures and are representative of three independent experiments with similar results. *p < 0.05, **p < 0.01 compared with control cultures. #p < 0.5, ##p < 0.01 compared with cultures without stimulant for closed circles and cultures stimulated with NK-4 only for open circles