Human granulocyte- and granulocyte-macrophage-colony stimulating factors are chemotactic and "competence" growth factors for human mesenchymal cells.

Mesenchymal cell migration and replication are biological events regulated by cytokines released by several cell types. Human granulocyte-colony stimulating factor (G-CSF) and macrophage-granulocyte-CSF (GM-CSF) were evaluated for chemotactic and growth activity for mesenchymal cells, using modified Boyden chemotactic chambers and complementation tests with human mesenchymal cells as target cells. G-CSF and GM-CSF, at biological concentrations, were demonstrated to be chemotactic and "competence" growth factors for these cells. Furthermore, G-CSF chemotactic activity was truly chemotactic (as demonstrated by checkerboard analysis) and significantly more potent than GM-CSF', while GM-CSF "competence" activity was significantly higher than G-CSF'. These observations suggest the potential role of these cytokines in tissue repair and fibrosis.