Comparative studies on eosinophil chemotactic factors during leukocyte migration under agarose

Several known eosinophil chemotactic factors are compared with regard to their biological behavior during in vitro migration under agarose: zymosan activated serum (Zas), containing the chemotactic fragment C5a, the lymphokine eosinophil stimulation promoter (ESP), neutrophil-derived eosinophil chemotactic factor (ECF) and the N-formyl-methionyl-phenylalanine (NFMP) peptide induced chemotaxis and chemokinesis of granulocytes. All factors except NFMP attracts eosinophils and neutrophils. ECF alone selectively enhances eosinophil migration, and NFMP is inactive towards eosinophils. ESP is the least potent factor but affects eosinophil migration over a prolonged period of time. These different biological properties of the chemotactic factors may help to explain the differential influx of eosinophil and neutrophil leukocytes to tissue sites.