[Supportive effects of human aorta-gonad-mesonephros-derived stromal cells on umbilical cord blood LTC-IC].

The objective of this study was to explore the supportive effects of human aorta-gonad-mesonephros (AGM)-derived stromal cells on human umbilical cord blood long-term culture-initiating cells (LTC-IC). A co-culture system was established with human AGM stromal cells and umbilical cord blood CD34(+) cells. Different stromal cells derived from human AGM region (hAGM S1-S5) were plated on 24-well plates as feeder cells. CD34(+) cells were positively selected from human umbilical cord blood through immunomagnetic bead selection method, seeded on the feeder cells, and co-cultured for 8 weeks. The hematopoietic cells were collected at 5, 6, 7 and 8 weeks for CFC analysis. Frequencies of LTC-IC in umbilical cord blood CD34(+) cells after co-culture with AGM stromal cells were detected through limiting dilute analysis (LDA). The results showed that there was no any hematopoietic CFC in the feeder cell-free culture system after 5 weeks of co-culture. However, in AGM feeder cells culture systems, there were still CFCs after 5 weeks of co-culture, which indicated that human AGM stromal cells could maintain LTC-IC in vitro. In groups of hAGM feeders, hAGMS3 and S4 had better supportive effects than other AGM groups (P < 0.05). The absolute number of LTC-IC in hAGM S3 and S4 culture systems got expansion up to (176 +/- 46)% and (187 +/- 52)% respectively without significant difference between hAGMS3 and S4 (P > 0.05). It is concluded that human AGM stromal cells S1-S5 support the maintenance of umbilical blood LTC-IC in vitro, while hAGMS3 and S4 cells have better effects on maintaining LTC-IC and expansion of LTC-IC.