Expression data from C/EBP alpha induced transdifferentiation of pre-B cells into macrophages

Earlier work has shown that pre-B cells can be converted into macrophages by the transcription factor C/EBP? at very high frequencies. Using this system we have now performed a systematic analysis of the question whether during transdifferentiation the cells transiently reactivate progenitor restricted genes or even retrodifferentiate. A transcriptome analysis of transdifferentiating cells showed that most genes are continuously up or downregulated, acquiring a macrophage phenotype within 5 days. In addition, we observed the transient reactivation of a subset of immature myeloid markers, as well as low levels of the progenitor markers Kit and Flt3 and a few lineage inappropriate genes. However, we were unable to observe the re-expression of cell surface marker combinations that characterize hematopoietic stem and progenitor cells (HSPCs), including c-Kit and Flt3. This was the case even when C/EBPalpha was activated in pre-B cells under culture conditions that favor HSPC growth or when the transcription factor was activated in a time limited fashion. Together, our findings are consistent with the notion that the conversion from pre-B cells to macrophages is mostly direct and does not involve overt retrodifferentiation.

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Di Tullio A, Vu Manh TP, Schubert A, Castellano G, Månsson R, Graf T