Enhancement of human eosinophil- and neutrophil-mediated killing of schistosomula of Schistosoma mansoni by reversed type (IgE-mediated) anaphylaxis, in vitro
Moqbel, R.; MacDonald, A.J.; Kay, A.B.
Clinical and Experimental Immunology 59(3): 577-586
1985
ISSN/ISBN: 0009-9104 PMID: 3987093 Document Number: 261925
A model for studying the effect of in vitro anaphylaxis on granulocyte-mediated killing of helminthic larvae (schistosomula (Sch) of S. mansoni) was developed using human peripheral blood leukocytes. Leukocytes were incubated with either an F(ab')2 rabbit anti-human IgE ( alpha E) or a control F(ab')2 prepared from non-specific rabbit IgG ( alpha Ec). A time-dependent enhancement of eosinophil- and neutrophil-mediated complement (C) or antibody- (Ab) dependent killing of Sch was observed following incubation with alpha E, but not alpha Ec. Optimal enhancement of granulocyte killing was dependent on the concentration of alpha E, preincubation of granulocytes with alpha E prior to addition to C coated Sch, as well as the granulocyte:Sch ratio. Baseline killing of Ab and/or C coated Sch by eosinophil rich cells was significantly greater than neutrophil rich suspensions and both were proportionally increased following incubation with alpha E. Enhanced eosinophil and neutrophil killing by alpha E required the presence of mononuclear cells containing basophils, whereas there was no difference in the killing of C or Ab coated Sch when eosinophils or neutrophils alone were incubated with alpha E or alpha E. This IgE and leukocyte-dependent model might facilitate the isolation and identification of the pharmacological mediator(s) of hypersensitivity which enhance eosinophil or neutrophil killing of appropriately opsonized helminthic larvae.