D that within this model system differentiation was ordered and progressed

D that within this model system differentiation was ordered and progressed along the normal developmental pathway as judged by the sequentialHuman T Lineage Development In VitroFigure 6. Dll-4 and IL-7 are up-regulated by three-dimensional cultured keratinocytes. (A) Dll-4 gene expression is strongly up-regulated in 3D cultured Hacat keratinocytes either alone or in the presence of fibroblasts. The differences between 3D and 2D either Hacat (*p<0.01) or cocultures (**p<0.05) are significant. No differences were observed in the housekeeping gene expression in all the conditions tested. The 56-59-7 results shown are the average of three different experiments ?standard deviation. (B) IL-7 gene expression is strongly up-regulated in 3D cultured Hacat keratinocytes either alone or in the presence of fibroblasts. The differences between 3D and 2D either Hacat (*p<0.05) or co-cultures (**p<0.05) are significant. No differences were observed in the housekeeping gene expression in all the conditions tested. The results shown are the average of three different experiments ?standard deviation. (C) Time dependent up-regulation of the Dll-4 gene in three-dimensional Hacat keratinocytes/ fibroblasts cocultures. A strong induction is observed during the first week and this high expression is maintained for about 10 days. The results shown are the average of three different experiments ?standard deviation and the differences between 2D and 3D within days 4-14 (* p < 0.01; ** p < 0.01; *** p <0.05; p < 0.01; p < 0.01), are all statistically significant. (D) Dll-4 protein expression in 2D and 3D cultured Hacat keratinocytes. The western blot image shows different parts of one single gel. The average of Dll-4 level of expression normalized to actin from three different experiments ?standard deviation differs between the 2D and 3D environment and the difference is significant (p< 0.001).doi: 10.1371/journal.pone.0069572.gappearance of the expected intermediate stages in the production of mature thymocytes [13?5]. CD34+ cells seeded onto monolayer cultures of fibroblasts and keratinocytes seeded at the same ratio failed to differentiate and died within 3 days. These cultures were provided with the same cocktail of growth factors as the three dimensional cultures which indicated significant changes in thekeratinocytes and fibroblasts induced by this conformational change.Analysis of the three-dimensional matrixExamination of the attached cells collected from the matrices after 1 or 2 weeks of culture revealed a greater increase in the number of keratinocytes compared with the fibroblasts (FigureHuman T Lineage Development In VitroFigure 7. TREC analysis shows that thymocytes were generated de novo. . (A) TREC was amplified from DNA from cells generated in the matrices after 10 days of co-culture but not from DNA from cord blood separated precursors. RPS-29 housekeeping gene was amplified in both cases. TREC and RPS-29 were respectively identified as a band of 192 and 142 base pairs. (B) TREC/CD3+ ratios from cord blood T cells and thymocytes generated in the matrices. The latter cells show higher level of TREC expression per cell compared 23977191 to T cells which were separated from cord blood. The results shown are the average of three different experiments?standard deviation and the difference is significant (p < 0.001).doi: 10.1371/journal.pone.0069572.g5A) and at 2 weeks the keratinocytes constituted 84 ?4.5 of total cells (Figure 5B). The cells attached to the scaf.