title: Killing of juvenile Fasciola hepatica by purified bovine eosinophil proteins.
abstract: Eosinophils were isolated from the mammary gland of Fasciola hepatica-infected cattle by intramammary infusion with a crude extract from adult F. hepatica. Up to 5 x 10(9) eosinophils with a purity of over 90% could be obtained from a single quarter of the gland. The major contaminating cells were monocytes which reached their peak several days following the eosinophil peak. Two major proteins were isolated from bovine eosinophil granules, a high molecular weight peroxidase-active protein and a smaller molecular weight predominantly basic protein. This smaller protein was thought to be the bovine equivalent of guinea-pig and human major basic protein (MBP), although it possessed an unusually high concentration of cysteine. The bovine MBP had a profound effect on juvenile F. hepatica in vitro causing damage and death at concentrations down to 1 x 10(-6) M. The damage was detected by a 51Cr release assay and/or a viability assay involving microscopical examination of the flukes. Other cations, especially protamine sulphate, were also shown to kill flukes, although both lysozyme, found in neutrophils, and the peroxidase-positive peak from bovine eosinophils were unable to mediate any detectable damage.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D002417:Cattle; D002470:Cell Survival; D004804:Eosinophils / Q000276:immunology*; D005210:Fasciola hepatica; D005211:Fascioliasis / Q000276:immunology*; D005260:Female; D007958:Leukocyte Count; D008970:Molecular Weight
chemical_list: D000596:Amino Acids; D001798:Blood Proteins