Abstract

Migration-inhibitory factor (MIF) is a lymphokine that acts to localize mononuclear phagocytes (monocytes and macrophages) and perhaps to activate them. Mo cells are a human T cell leukemia virus II-infected T cell line previously shown to secrete large quantities of MIF upon stimulation with phytohemagglutinin and phorbol myristate acetate. MIF was purified from Mo cell-conditioned medium by gel filtration, phenyl- Sepharose affinity chromatography, isoelectrofocusing, and reverse- phase high-performance liquid chromatography (RP-HPLC). Overall purification was 6,000-fold. The purified MIF fraction was found to display potent colony-stimulating factor (CSF) activity when assayed on human bone marrow cells. The double peak of MIF activity as shown by C 18-RP-HPLC coincided with the double peak of CSF activity. A monoclonal antibody selected for its anti-MIF activity absorbed both the CSF and the MIF activity. These findings indicate that MIF and CSF are either identical molecules or closely related molecules with common structural elements.

This content is only available as a PDF.