Purification and characterization of a high molecular weight eosinophil chemotactic factor from Schistosoma japonicum eggs.
A high m.w. eosinophil chemotactic factor (ECF-SjE) was isolated and purified from a soluble egg antigen preparation (SEA) of Schistosoma japonicum by gel filtration on Sephacryl S-200, anion-exchange chromatography on DE52, and isoelectric focusing. ECF-SjE had a m.w. of more than 900,000 and an isoelectric point of 4.1. It contained 40% (w/w) sugar residues and bound to concanavalin A (Con A). The chemotactic activity of ECF-SjE was heat stable (100 degrees C, 60 min) and resistant to pronase digestion, but was destroyed by periodate oxidation. IgG antibody to ECF-SjE was detected in the serum of a rabbit infected with S. japonicum, demonstrating the antigenic nature of ECF-SjE. The antigenicity of ECF-SjE was also sensitive to periodate oxidation. Thus, ECF-SjE is a glycoprotein or proteoglycan from the eggs of S. japonicum, and the sugar chain is important for the expression of chemotactic and antigenic activities. However ECF-SjE differs from the major allergenic components of S. japonicum (JEAL) in m.w. and isoelectric point. A low m.w. eosinophil chemotactic factor was also detected in SEA. Together they are proposed to have a role in the direct accumulation of eosinophils in the egg-induced granulomas in S. japonicum infection.
D000818:Animals; D001666:Binding Sites, Antibody; D002630:Chemotactic Factors / Q000302:isolation & purification*; D002631:Chemotactic Factors, Eosinophil / Q000302:isolation & purification* / Q000494:pharmacology; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007122:Immunoelectrophoresis; D007525:Isoelectric Focusing; D051379:Mice; D008970:Molecular Weight; D010063:Ovum / Q000276:immunology*; D011402:Pronase / Q000494:pharmacology; D011817:Rabbits; D012549:Schistosoma japonicum / Q000276:immunology; D012552:Schistosomiasis / Q000276:immunology* / Q000469:parasitology
D002630:Chemotactic Factors; D002631:Chemotactic Factors, Eosinophil; D011402:Pronase