A subset of mobilized human hematopoietic stem cells express germ layer lineage genes which can be modulated by culture conditions.

Adult bone marrow contains stem cells that replenish the myeloid and lymphoid lineages. A subset of human and mouse CD34+ bone marrow stem cells can be propagated in culture to autonomously express embryonic stem cell genes and embryonic germ layer lineage genes. The current study was undertaken to determine whether these CD34+ stem cells could be obtained from human blood, whether gene expression could be modulated by culture conditions and whether the cells produce insulin. Human peripheral blood buffy coat cells and mobilized CD34+ cells from human blood and from blood from C57Bl/6 J mice were cultured in hybridoma medium or neural stem cell induction medium supplemented with interleukin (IL)-3, IL-6, and stem cell factor (SCF). Changes in mRNA and protein expression were assessed by Western blot analysis and by immunohistochemistry. Mass spectrometry was used to assess insulin production. We were able to culture CD34+ cells expressing embryonic stem cell and embryonic germ layer lineage genes from adult human peripheral blood after standard mobilization procedures and from mouse peripheral blood. Gene expression could be modulated by culture conditions, and the cells produced insulin in culture. These results suggest a practical method for obtaining large numbers of CD34+ cells from humans to allow studies on their potential to differentiate into other cell types.