Interaction of Lectins with Human IgE: IgE-Binding Property and Histamine-Releasing Activity of Twelve Plant Lectins

Abstract

We examined the IgE-binding reaction and the histamine-releasing response of basophils to a panel of 12 lectins: concanavalin A (Con A), Lens culinaris hemagglutinin (LcH), Pisum sativum agglutinin (PSA), wheat germ agglutinin (WGA), soybean agglutinin (SBA), Bauhinia purpurea agglutinin (BPA), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA-I), Lotus tetragonolobus agglutinin (Lotus A), Ulex europeus agglutinin I (UEA-I), phytohemagglutinin E (PHA-E) and phytohemagglutinin L (PHA-L). IgE from allergic patients bound with high affinity to Con A, LcH, PSA, RCA-I and PHA-E, and with lower affinity to WGA, BPA, Lotus A and UEA-I, but they did not bind to SBA, PNA or PHA-L. There was no apparent individual difference in the reactivity of IgE to these lectins between 10 IgE preparations from allergic patients. The binding to these lectins, except Lotus A and UEA-I, were competitively inhibited by the lectin-specific sugars or glycopeptide. Upon stimulation by Con A, LcH, PSA, WGA, RCA-1 and PHA-E, leukocytes from allergic patients showed a significant release of histamine, but cells from IgE-deficient subjects did not respond to these lectins. The histamine-releasing responses by these lectins were also inhibited by specific sugars or glycopeptides.

Inhibitory Effects of Sialic Acid- or N-Acetylglucosamine-Specific Lectins on Histamine Release Induced by Compound 48/80, Bradykinin and a Polyethylenimine in Rat Peritoneal Mast Cells

“…The inhibitory effects of lectins demonstrated in this study were quite different from those effected by the bind ing of lectins to IgE molecules; in the latter case, lectins bound to sugar residues of IgE molecules instead of mast cell glycoproteins (32). Analyses using lectins revealed that the PGE1 receptor of mastocytoma P815 cells (33), substance P receptor of porcine brain (34) and M2-mus carinic receptor of rat (35) were indeed glycoproteins.…”

Carbohydrate Epitopes and Their Relevance for the Diagnosis and Treatment of Allergic Diseases

“…For quite some time, many allergists remained skeptical about the concept of IgE antibodies against carbohydrate determinants. It was suggested that the interaction between IgE and allergen extract was not based on a paratope-epitope, but on a carbohydrate (on IgE molecule) lectin (in the allergen extract) interaction [2]. Others thought that it was impossible to have carbohydrate-specific IgE antibodies because carbohydrate determinants were supposed to be T cell independent.…”

Datura stramonium Agglutinin Released Histamine from Rat Peritoneal Mast Cells That Was Inhibited by Pertussis Toxin, Haptenic Sugar and N-Acetylglucosamine-Specific Lectins: Involvement of Glycoproteins with A-Acetylglucosamine Residues

“…WGA, PHA-E4 and STA are specific for G1cNAc, espe cially the bisecting GlcNAc residues; and MAM is a Sia specific lectin. Thus the sugar-specificities of the inhibi tory lectins were quite different from those of lectins that bind to IgE-IgE receptor complexes or IgE (11,12). The binding of inhibitory lectins to the corresponding glycoproteins interfered with the mast cell activation in duced by compound 48/80, bradykinin or PEI6, because the specific haptenic sugars of the lectins protected the cells from inhibition by the lectins.…”