Specificity of Lactoferrin as an Inhibitor of Granulocyte-Macrophage Colony-Stimulating Activity Production From Fetal Mouse Liver Cells

Fetal mouse liver cultures capable of producing both erythropoietin (Ep) and granulocyte-macrophage colony stimulating activity (GM-CSA) were used to study the specificity of lactoferrin as an inhibitor of the production of GM-CSA. Both a granulocyte-derived colony-inhibiting activity (CIA) and lactoferrin inhibited GM-CSA production while having no effect on Ep production. These results demonstrate the specificity of lactoferrin for GM-CSA production.