Expression of co-stimulatory markers CD80 and CD40 on the surface of DCs conditioned with culture medium from MODE-K cells ± L. gasseri OLL2809/L13-Ia. Before a 6-h LPS pulse, iDCs were challenged for 24 h with medium from: untreated MODE-K cell culture (SupMODE, C); MODE-K cells following TNF-α stimulation (D); MODE-K cells following probiotic co-incubation (E and F); irradiated OLL2809 or L13-Ia (24 h incubation; SupOLL2809 and SupL13-Ia, G and H). iDCs were also directly challenged for 24 h with irradiated bacteria (I and J). iDCs (A) and untreated mDCs (B) were used as controls. DCs were stained for CD40 and CD80 and analyzed by FACS. Data were collected from ungated cells and are representative of three independent experiments.