Eosinophil-activating factor (EAF) production by a human cell line (ESH 98) stimulated with tumour necrosis factor.

A new cell line has been produced by fusing human cervical keratinocytes with HeLa cells. This cell line secretes eosinophil-activating activity upon stimulation with tumour necrosis factor (TNF). About one-third of the eosinophil-activating activity co-purifies with eosinophil-activating factor (EAF) from mononuclear cell supernatants. The purification procedure indicates that it resembles EAF in molecular weight and acidity. It also resembles EAF in its effect on eosinophils. Not only does it enhance the cytotoxic activity of eosinophils to antibody-coated schistosomula of Schistosoma mansoni, but it also increases the oxidative activity of eosinophils, as measured by reduction of nitroblue tetrazolium, and changes the morphology of eosinophils, affecting the distribution of F-actin in the cell.