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A glycoprotein from Schistosoma mansoni eggs binds non‐antigen‐specific immunoglobulin E and releases interleukin‐4 from human basophils
Author(s) -
Haisch Karin,
Schramm Gabriele,
Falcone Franco H.,
Alexander Christian,
Schlaak Max,
Haas Helmut
Publication year - 2001
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1046/j.1365-3024.2001.00392.x
Subject(s) - biology , schistosoma mansoni , glycoprotein , antigen , immunoglobulin e , immune system , antibody , concanavalin a , lysozyme , microbiology and biotechnology , interleukin 4 , immunology , biochemistry , in vitro , schistosomiasis , helminths
We have recently shown that soluble extracts from Schistosoma mansoni eggs (SmEA) triggered basophils from nonsensitized donors to rapidly release interleukin (IL)‐4. Assuming that this mechanism might play a role in vivo in biasing the immune response towards a Th2 phenotype, we determined basic properties of the IL‐4‐inducing activity contained in SmEA. Sensitivity to pepsin digestion indicated protein nature. Binding to and specific elution from Concanavalin A‐sepharose suggested that this protein contains mannose residues, thus being a glycoprotein. The IL‐4‐inducing activity was stable for 30 min at room temperature towards shifting the pH between 3 and 10. When incubated at 100°C, it was stable at pH 3, but less stable at neutral and alkaline pH. Electroelution from an SDS‐PAGE gel indicated an apparent molecular weight of the IL‐4‐inducing activity between 31 and 66 kDa. Although binding to purified human immunoglobulin E (IgE) and activating basophils IgE‐dependently, SmEA appears to activate basophils in a non‐antigen‐specific way, since the cells were purified from noninfected donors. Because the IL‐4‐inducing activity was found to be released from eggs, it could be an important factor in the environment of the eggs skewing the immune response towards the Th2 phenotype.