[Detection of high interleukin 6 concentrations in miniaturized human bone marrow long-term cultures]

The long-term bone marrow culture system (LTBMC) consists of an inductive environment provided by a marrow-derived adherent layer which induces pluripotent stem cell replication. The activity of IL-6 was analyzed in micro LTBMC as a potential stem cell regulator. Immediately after initiation there was a tremendous increase in IL-6 activity. With each refeeding, IL-6 levels rose until confluency of the stromal layer was reached at week two to three post initiation. As a working hypothesis for further investigations, we suggest the immediate shift of stem cells after refeeding from a non-cycling into a cycling state might be mediated by the steep increase of IL-6 alone or in cooperation with other factors.