Development of an efficient serum-free semisolid culture system for the evaluation of hematopoietic progenitors.

Three different combinations of serum-free (SF) media proposed by Drouet et al., Ieki et al., and Wu et al. were tested to assess their ability to replace fetal calf serum (FCS) in a human hematopoietic progenitor semisolid culture system using human bone marrow and peripheral blood stem cells. This study confirmed that two (Drouet and Wu) of the three SF media tested were able to induce progenitor growth in the presence of either 5637-conditioned medium or a defined combination of growth factors: stem cell factor (SCF), interleukin-1 (IL-1), interleukin-3 (IL-3), and erythropoietin (EPO). The best results were obtained using the SF media described by Wu. The number of 5637-stimulated CFU-GM obtained with the Wu SF media was not different from that obtained with FCS-supplemented media when cultures were assessed on day 14 (79 +/- 14 versus 104 +/- 17), day 18 (64 +/- 11 versus 79 +/- 12), or day 21 (58 +/- 13 versus 62 +/- 12). Similar findings were obtained when the previously defined combination of growth factors was used to stimulate progenitor growth. Because the Wu medium was the most efficient SF medium to promote hematopoietic progenitor growth, we attempted to improve its efficacy by modifying the concentrations of the various components. A reduction in the concentration of bovine serum albumin (BSA) dramatically reduced the total number of clonogenic elements. Soybean lectin was not essential for colony proliferation; however, its presence had an favorable effect on the overall appearance of the colonies (greater number of cells per colony).(ABSTRACT TRUNCATED AT 250 WORDS)