IL-10 increases the number of CFU-GM generated by ex vivo expansion of unmanipulated human MNCs and selected CD34+cells

BACKGROUND: Ex vivo expansion strategies with different cytokine combinatio ns are currently used by several groups as a means of increasing the number of HPCs for a variety of special clinical applications. Because there is l ittle information on the potential role of IL-10 in such ex vivo expansion models, the effect of this cytokine on the generation of myeloid progenitor cells in suspension cultures was investigated. STUDY DESIGN AND METHODS: On the basis of data from the literature and from new experiments, the combination of SCF and IL-3 at concentrations of 100 ng per mt and 100 U per mt, respectively, was chosen as the standard cockta il. The addition of IL-10 to such cultures resulted in a marked and dose-de pendent potentiation of myeloid progenitor cell production. RESULTS: Using unmanipulated leukapheresis components from 13 individuals ( including lymphoma and cancer patients and normal donors), the expansion mu ltiple of CFU-GM after 14 days as compared with pre-expansion values was 9. 54 +/- 2.31 times by SCF/IL-3 and 46.38 +/- 7.37 times by the combination o f SCF/IL-3 and 100 ng per mt of IL-10 (p <0.001). IL-10 also potentiated CF U-GM generation from selected CD34 PBMNCs (n = 9) with an expansion of 17.2 2 +/- 7.04 times versus 45.67 +/- 16.78 times using the SCF/IL-3 and SCF/IL -3/IL-10 combination, respectively (p <0.05). Moreover, expansion-promoting effects of IL-10 were observed in liquid cultures containing MNCs from bon e marrow (n = 4) and cord blood (n = 3), but did not reach statistical sign ificance because of the small number of samples. CONCLUSION: These results suggest IL-10 as a useful cytokine to optimize pr ogenitor cell-expansion strategies for clinical application.