Induction of eosinophil chemotactic factor production from human peripheral blood mononuclear cells by solubilized BALL-1, a B cell lymphoma line.

We have previously shown that irradiated BALL-1, a B lymphoma line, stimulates OKT4 T cells to produce a unique eosinophil chemotactic factor (ECF) which suppresses the respiratory burst of eosinophils. In the present experiments, we found that solubilized BALL-1 also stimulated peripheral blood mononuclear cells (PBMC) to produce ECF activity in a dose-dependent manner. PBMC treated with solubilized BALL-1 produced ECF within 24 h. ECF production-inducing factor (ECF-IF) had affinity with lentil lectin beads, suggesting that ECF-IF has glucose or mannose as carbohydrate moieties. Furthermore, we found that ECF-IF activity was comprised of at least four ECF-IF with different isoelectric points (pI): ECF-IF1 had a pI of 4-5, ECF-IF2 a pI of about 6, ECF-IF3 a pI of about 7, and ECF-IF4 a pI of about 8. ECF-IF1 stimulated PBMC to produce mainly an ECF with a pI of about 7-8, whereas the rest of ECF-IF induced an ECF with a different pI. The present results suggest that the membrane glycoproteins of some tumors, at least, partly contribute to tissue eosinophilia in the stroma of the malignant tumor by inducing ECF production from PBMC.