Detection of the lymphokine migration inhibitory factor in normal and disease-affected lung by antibody and by its major binding protein, the interferon antagonist sarcolectin.

Human migration inhibitory factor (MIF) is suggested to play a notable role in regulation of macrophage functions in host defense. A major binding component for the lymphokine in human tissue is the interferon antagonist sarcolectin. This high-affinity interaction gives access to MIF by affinity chromatography on immobilized sarcolectin and may be of significance for in situ activity of MIF. Localization of MIF is one step towards answering this question. Labelled sarcolectin and MIF-specific antibodies can be employed to analyze the expression of the factor. Surgical specimens of 74 patients, who underwent lobe/lung resection or diagnostic biopsy, were fixed with buffered formalin and embedded in paraffin. The material consisted of 36 cases of morphologically normal lung parenchyma of patients, suffering from bronchial carcinoma, of 16 cases with sarcoidosis, of 15 cases with tuberculosis and of 7 cases with idiopathic interstitial pneumonitis. The two types of probe to visualize presence of MIF invariably showed the same level of reactivity, underscoring the potential physiological significance of sarcolectin-MIF interaction. In detail, all cases with pneumonitis, most tuberculosis-affected as well as normal cases and 44% of the cases with sarcoidosis were positive. All positive cases with sarcoidosis and some cases from the other groups revealed accessible binding sites for biotinylated MIF.