UC San Diego

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that stimulates the survival, proliferation, and differentiation of hematopoietic precursor cells of eosinophils, neutrophils, monocytes, macrophages, and dendritic cells. Recombinant human GM-CSF (rhGM-CSF) has not only been commonly used to stimulate varying in vitro hematopoietic cell differentiations and activations, but it has also been proposed to have great potential for clinical use. With its growing demand, many studies have been done to optimize the production and bioactivity of rhGM-CSF. Bacterial, yeast, plant, and mammalian cell-lines have all been successfully used to produce rhGM-CSF, but each having differing characteristics. In this study, Chinese hamster ovary (CHO) cells were used to produce rhGM-CSF conditioned media (CM) since mammalian cell-lines have shown to produce rhGM-CSF that most closely resembles the naturally produced human GM-CSF. The characteristics and bioactivity of CHO produced rhGM-CSF CM and commercial E. coli rhGM-CSF were compared by Western Blot, stimulation of THP-1 cells, and dendritic cell (DC) differentiation. The molecular weight bands observed on the Western Blot confirmed that the rhGM-CSF CM bands were similar to the reported GM-CSF proteins produced by human cells, whereas commercial E. coli rhGM-CSF bands were different. However, no significant difference was observed between the bioactivity of each rhGM-CSF