Neopterin Acting as a Bone Marrow Stem Cell Factor on Early Common Haematopoietic (Myeloid) and Stromal (Dendritic, CD34+) Cell Progenitors in vitro

Abstract

The in vitro response of early haematopoietic progenitors or stem cells, common for myeloid (granulocyte, eosinophil, megacaryocyte) and marrow stromal (including dendritic CD34+) cells series, to neopterin, exogenously added to the liquid- and semi-liquid (agar-) mouse bone marrow cultures, at doses 12.5 - 25 Jlg/ml culture medium, has been studied. The results obtained show a significant stimulation of common myeloid and stromal dendritic cell (CD34+) progenitors' proliferation and/or differentiation as early as 24h after the in vitro treatment of marrow cultures with neopterin. On day 4 of cultivation the granulocyte/macrophageal proliferation and differentiation has been attenuated giving place to the marrow stromal dendritic cell (probably CD34+) differentiation. The engagement of the nuclear proliferative factor NF-K B may playa role in the light of recent data that neopterin could activate this transcriptionally active nuclear factor. The significance of clonal selective stimulation of healthy (but not of leukaemic) dendritic CD34+ cells in some pathological cases as acute myeloid leukaemia has been also discussed because neopterin could be a more efficient marrow stem cell factor than cytokine cocktails with granulocyte/macrophage-colony stimulating factor. The ex vivo or clinical application of neopterin, alone and/or in specific combinations with other cytokines, in the induction of marrow myeloid and stromal cell proliferation and differentiation towards the dendritic (CD34+) cells merits further investigations ..

Keywords

• mouse
• bone marrow
• neopterin
• marrow stem cell factor
• haematopoietic progenitors
• stromal dendritic cell progenitors
• dc (cd 34+)
• nuclear factor-k b