Figure 5: MSCs increase IL-10 production in U937-MSC co-culture. Supernatants collected from MSC culture (150,000cells/well) alone, and U937 culture (3x105/well and 7.5x105/well) alone did not contain any IL-10, as quantified by cytokine bead assay for flow cytometry (BD Biosciences, San Jose, CA). Both co-culture groups (in ratios 1:2 and 1:5, MSCs:U937s) significantly increased IL-10 production in response to stimulation with LPS (5ng/mL).