CHEMOTACTIC AND CHEMOKINETIC ACTIVITIES OF STEM-CELL FACTOR ON MURINEHEMATOPOIETIC PROGENITOR CELLS

We investigated the effects of stem cell factor (SCF) on the migration of murine bone marrow hematopoietic progenitor cells (HPC) in vitro u sing a modification of the checkerboard assay. Chemotactic and chemoki netic activities of SCF on HPC were evaluated by the numbers of HPC mi grated on positive and negative gradients of SCF, respectively. On bot h positive and negative gradients of SCF, HPC began to migrate after 4 hours incubation, and their numbers then increased time-dependently. These results indicated that SCF functions as a chemotactic and chemok inetic agent for HPC. Analysis of types of colonies derived from the m igrated HPC showed that SCF had chemotactic and chemokinetic effects o n all types of HPC. When migrating activities of other cytokines were examined, interleukin (IL)-3 and IL-11 also affected the migration of HPC, but the degrees of each effect were lower than that of SCF. The r esults of the present study demonstrated that SCF is one of the most p otent chemotactic and chemokinetic factors for HPC and suggest that SC F may play an important role in the flow of HPC into bone marrow where stromal cells constitutively produce SCF. (C) 1996 by The American So ciety of Hematology.