Characterization of human lymphocyte derived chemotactic factors for mononuclear phagocytes--I. Production and detection.

Human peripheral blood mononuclear cells were isolated on a large scale by leukapheresis of either individual donors or pooled cell concentrates supplied by a local blood bank. Optimal conditions with respect to cell density, lectin (soluble and insoluble Concanavalin A; phytohemagglutinin) concentration and culture time were established for monocyte chemotactic factor (LMCF) production. LMCF was assayed on highly purified human monocytes/macrophages which had been kept in culture up to 4 days for optimal expression of response to LMCF. Chemotaxis assays were performed in a novel type multichamber assembly and migrated cells were enumerated by enzyme-linked immunosorbent assay. Based on the described methodology it is possible to produce litre quantities of LMCF and assay large numbers of samples both of which are prerequisites for chemical and functional characterizations of LMCF.