Hematopoietic Stem and Progenitor Cell Expansion in Contact with Mesenchymal Stromal Cells in a Hanging Drop Model Uncovers Disadvantages of 3D Culture

Figure 6

The 3D model is not favorable for the enhancement of primitive progenitors. Multilineage differentiation capacity of 10³ HSPCs expanded in the hanging drop model or in a 2D culture plate was investigated after one week of culture with or without MSCs (coculture and monoculture, resp.) in a CFU assay. Results were compared to the CFU forming potential of 10³ freshly isolated cord blood-derived HSPCs (control). (a) The BFU-E percentage of the total CFU number increased after ex vivo expansion at the expense of CFU-GEMM for all culture conditions. The CFU-GM percentage of the total CFU number was considerably augmented only for HSPCs in 2D coculture. (b) The CFU fold increase was obtained by comparison with colony numbers of nonexpanded cells and was calculated using the proliferation rate of HSPCs under the respective culture conditions. HSPCs expanded on an adherent MSC layer produced the largest number of total colonies. Values are expressed as mean ± standard deviation of three independent experiments from three donors. One-way ANOVA was applied for statistical analysis (; ; ).