Pre-stimulation of the human bone marrow CD34+ cells before storage at 4 degrees C with the early acting cytokines enhance their survival and increase proliferative potential. Transplantological implications.

The aim of this study was to evaluate whether short prestimulation of the human bone marrow CD34+ cells before storage at 4 degrees C with early acting cytokines would improve their subsequent survival and clonogenecity. To address this question the cells were placed in iscove medium supplemented with 20% BCS and stimulated for 24 hours in 37 degrees C incubator with different combination of the early acting cytokines (KL, IL-1 beta, IL-3, IL-6). Subsequently the cells were shifted to 4 degrees C. On day 6 the cells were plated in methylcelulose cultures and stimulated to growth CFU-GM colonies. It had been found that 24 hours long pre-stimulation with early acting cytokines significantly enhances the survival of the CD34+ clonogeneic progenitors stored subsequently at 4 degrees C. The CD34+ cell prestimulated for 24 hours at 37 degrees C with KL + IL-3 and than shifted to 4 degrees C formed more than twice as much CFU-GM colonies in comparison to the cells stored whole time at 4 degrees C even in the presence of KL + IL-3. Therefore we suggest, that if there is a need to store bone marrow cells before transplantation for short time they should be prestimulated with early acting cytokines for 24 hours in liquid culture at 37 degrees C first and than placed at 4 degrees C. The data presented in this paper should be in the future confirmed in in vivo SCID animal model to evaluate the repopulation ability of marrow cells pre-stimulated before short term storage at 4 degrees C with early acting cytokines to enhance the proliferative potential of the transplant and to shorten the dangerous aplastic phase in the patients after transplantation.