Surface proteins of the human eosinophil. II. Effects of Schistosoma mansoni larvae on eosinophil surface proteins.

Incubation of eosinophils with schistosoma of Schistosoma mansoni in vitro induces changes in the eosinophil membrane. Cell surface proteins were blocked with unlabelled iodide and then, after incubation with schistosomula, newly accessible proteins were detected by lactoperoxidase catalysed iodination with radioactive iodide. Normal turnover restores several proteins to the eosinophil surface, but the schistosomula specifically induced the appearance of a protein of mol. wt 18K. This protein has previously been detected when eosinophils interact with antibody coated agar layers. Soluble factors released by schistosomula induced the appearance of enhanced levels of 16 and 18K proteins. It has previously been shown that proteins involved in binding of eosinophils to IgG coated antigen coupled cellulose have mol. wts of 16K and 18K.