RELEASE OF PLATELET-ACTIVATING FACTOR (PAF)-LIKE MATERIAL FROM HUMAN LYMPHOID-CELL LINES

Abstract

The release of platelet-activating factor(PAF)-like material was evaluated from 8 B and T human leukemic cell lines and from 3 lymphoblastoid cell lines obtained after Epstein-Barr virus (EBV) transformation. All cell lines were stimulated with ionophore A23187, phytohemagglutinin (PHA), or both either in the presence of or without acetyl CoA (AcCoA). After appropriate stimuli, all cell lines tested released PAF-like material irrespective of the surface phenotype and of the level of differentiation. Some cell lines released PAF-like material after stimulation with A23187 (Molt-4, Jurkat, 1031, Raji, FM007), others only if AcCoA was added to A23187 (CCRF/CEM, HUT 78, Daudi, Nalm-1). In some cases, PHA was capable of enhancing the effect of A23187 (Molt-4, HUT 78, Daudi, IBW4) and finally, in a lymphoblastoid cell line (WT20), the release of PAF-like material was achieved only in the presence of both A23187 and PHA. Human lymphoid cells both of B- and T-cell origin can release a PAF-like material after appropriate stimuli.