RESUMEN
To investigate effects of rhIL-17 on growth and development of mouse bone marrow progenitors andhuman cord blood LD34~+ stem cells. Methods: Mouse bone marrow progenitors were isolated by routine protocol, and CD34~+ stem cells were isolated from normal human cord blood by Mini-MACS, then cultured with rhIL-17 and/or GM-CSF/IL-4. The phenotypes of the cells were analyzed by FACS, IL-12 level was analyzed by ELISA and T cell stimulating activity in allo-MLR was determined by [~3H]-TdR incorporation. Results: Expression of MHC class II molecules and B7-2 on the surface of immature DC derived from mouse bone marrow progenitors was up-regulated by IL-17. The capacity of the cells to secrete IL-12 and their T cell stimulating activity were also enhanced. The cells showed the characteristics of mature DC. After cultured with IL-17 for 9 days, the number of CD34~+ stem cells increased by 2 times. The phenotypes of some cells were CDla~(high), B7-2~(high), and HLA-DR~(lwo). The cells could stimulate allo geneic T cells to proliferate but their capacity was lower than that of the cells cultured with IL-17 combined with GM-CSF. The cells cultured with IL-17 and GM-CSF proliferated markedly and the rate of CDla~+ and B7-2~+ cells increased significantly. The T cell stimulating activity of cells was also augmented. Conclusion: IL-17 could promote DC derived from mouse bone marrow progenitors to mature. When combined with GM-CSF, IL-17 could induce human CD34~+ stem cells not only to proliferate markedly but also to show characteristics of DC, indicating that CD34~+ stem cells might differentiate to DC by IL-17.