Isolation of Schistosoma japonicum egg-derived neutrophil stimulating factor: its role on eosinophil chemotactic factor release from neutrophils.

Neutrophil stimulating factor (NSF), which can stimulate polymorphonuclear neutrophils (PMNs) to release eosinophil chemotactic factor (ECF), was isolated from Schistosoma japonicum soluble egg extract (SEA). The release of ECF from PMNs began as early as 5 min after stimulation and reached a peak at 40 min, and was dependent on the concentration of SEA. After Sephadex G150 gel filtration, toluene extraction, Sephadex G25 gel filtration and Dowex 1 X 8 anion exchange chromatography, NSF was identified as a hydrophilic and negatively charged component with a molecular weight of about 1,000 daltons. It was heat-stable at 100 degrees C for 60 min. NSF was easily separable from SEA-derived neutrophil chemotactic factor or from SEA-derived ECF. PMNs are suggested to be one of the sources of ECF in the eosinophil accumulation of granulomatous lesions around the deposited eggs in schistosomiasis japonica.