INDUCTION OF AN EOSINOPHIL CHEMOTACTIC FACTOR PRODUCTION FROM T-LYMPHOCYTES BY A B-CELL LYMPHOMA LINE

Production of an eosinophil chemotactic factor (ECF) from human mononuclear leukocytes (MNL) was induced by coculture with an irradiated B cell lymphoma line, BALL-1. BALL-1 induced ECF production from OKT4-positive T lymphocytes without evident IL-2 production. Treatment of MNL with anti-IL-2 antibody failed to suppress the BALL-1-induced ECF production, whereas the treatment strongly inhibited IL-2-induced ECF production. Control supernatants of BALL-1 cells alone did not induce ECF production. BALL-1 fixed with periodate-lysine-paraformaldehyde, but not acetone or ethanol, induced evident ECF production. The isoelectric point of BALL-1-induced ECF (m.w. 10-30 kD) was around pl 7, whereas that of the IL-2-induced ECF was around pl 5. A combination of monoclonal antibodies against IL-3, IL-5, and GM-CSF suppressed the activity of the IL-2-induced ECF but not that of the BALL-1-induced ECF. BALL-1-induced ECF suppressed a respiratory burst from an eosinophilic cell line (YY-1) induced by N-formyl-L-methionyl-L-leucyl-L-phenylalanine, whereas the IL-2-induced ECF did not, suggesting that the biological function of these two ECF is different, at least in the effect on respiratory burst of eosinophils. From the present results we propose that one reason for infiltration of eosinophils into the stroma of tumors is that some tumor cells can stimulate OKT4-positive T lymphocytes to produce an ECF, and that eosinophils attracted by this ECF exhibit biological functions which are different from those of eosinophils attracted by other ECF.