ABSTRACT
PURPOSE: Receptors for the Fc of IgG(FcvR) and a beta2 integrin molecule, CD11c/CD18 are important in clearance of microbes by granulocytes. We performed an in vitro study on the effect of recombinant human granulocyte colony-stimulating factor(rhG-CSF), or granulocyte-macrophage colony-stimulating factor(rhGM-CSF) on the expression of Fc R II, Fc R III, CD11c and CD18 and respiratory burst function of granulocytes. METHODS: Peripheral blood was collected from six healthy adults. The isolated granulocytes were stimulated with rhG-CSF, 250mg/mL, rhGM-CSF, 100ng/mL or both of them for 1, 3, 9, 24, and 48 hours. Using flow cytometry, we compared the expression of the Fc R II, Fc R III, CD11c and CD18 of granulocytes before and after stimulation. We also the studied respiratory burst of granulocytes with chemiluminescence assay. RESULTS: Fc R II and CD18 expression were not changed significantly after stimulation. Fc R III expression was decreased significantly after stimulation with rhG-CSF, rhGM-CSF, or both of them. CD11c expression was increased initially but was found to decrease significantly after 9 hours of stimulation. Granulocytes treated with rhG-CSF, rhGM-CSF, or both displayed enhanced respiratory burst. Our results suggest that exposure of granulocyte to growth factor results in granulocyte activation. CONCLUSION: We have shown that rhG-CSF and rhGM-CSF resulted in an activation of peripheral blood granulocytes immunophenotypically and functionally.