Monoclonal antibody (II2C) to human lactoferrin inactivates the myelopoietic suppressive effect of human lactoferrin in vitro.

A mouse monoclonal antibody was prepared against purified and fully iron-saturated human breast milk lactoferrin (LF). This antibody was of the IgG1 subclass, and recognized LF biosynthesized in low-density normal human bone marrow cells and LF stored in normal human polymorphonuclear neutrophils. This antibody did not recognize purified and iron-saturated human transferrin. The antibody inactivated the suppressive effects of purified and iron-saturated human milk LF and LF present in crude extracts of normal polymorphonuclear neutrophils against the release of granulocyte-macrophage colony-stimulating factors from mononuclear blood leukocytes in vitro.