Human MSCs suppressed the initial generation of DCs from monocytes in the transwell chamber system. In the transwell chamber system separating MSCs from monocytes, CD14 and CD1a expression was investigated at multiple MSC/monocyte ratios (A) and at an MSC/monocyte ratio of 1:10 when supplemented with anti-IL-6 and anti-M-CSF neutralizing mAb. (B) 1, control; 2, anti-IL-6 neutralizing mAb; 3, anti-M-CSF neutralizing mAb; 4, anti-IL-6 and anti-M-CSF neutralizing mAb. Results of panel B are shown as mean ± SD from 3 independent experiments (^*P < .05, ^**P < .01).