Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E

Abstract

SummaryA major factor in non-allergic food hypersensitivity could be the interaction of dietary lectins with mast cells and basophils. Because immunoglobulin E (IgE) contains 10-12% carbohydrates, lectins can activate and degranulate these cells by cross-linking the glycans of cell-bound IgE. The present objective focuses on the effect of potato lectin (Solanum tuberosum agglutinin; STA) for its ability to release histamine from basophils in vitro and mast cells in vivo from non-atopic and atopic subjects. In this study, subjects were selected randomly based on case history and skin prick test responses with food, pollen and house dust mite extracts. Skin prick test (SPT) was performed with STA at 100 mg/ml concentration. Histamine release was performed using leucocytes from non-atopic and atopic subjects and rat peritoneal exudate cells. SPT on 110 atopic subjects using STA showed 39 subjects positive (35%); however, none showed STA-specific IgE; among 20 non-atopic subjects, none were positive by SPT. Maximal histamine release was found to be 65% in atopic subjects (n = 7) compared to 28% in non-atopic subjects (n = 5); the release was inhibited specifically by oligomers of N-acetylglucosamine and correlates well with serum total IgE levels (R 2 = 0·923). Binding of STA to N-linked glycoproteins (horseradish peroxidase, avidin and IgG) was positive by dot blot and binding assay. As potato lectin activates and degranulates both mast cells and basophils by interacting with the chitobiose core of IgE glycans, higher intake of potato may increase the clinical symptoms as a result of non-allergic food hypersensitivity in atopic subjects.

Identity of the immunomodulatory proteins from garlic (Allium sativum) with the major garlic lectins or agglutinins

“…Dietary lectins have been shown to release histamine from mast cells and basophils as a result of their interaction with cell-surface IgE molecules resulting in activation [42]. Earlier, it has been demonstrated from this laboratory that horse gram lectin (specificity for GalNAc) does not induce HR from leukocytes whereas potato lectin (specificity for core GlcNAc-GlcNAc) induces HR from leukocytes of atopic subjects [27,28]. Since core GlcNAc-GlcNAc and trimannosidic core are present in almost all of the glycans of N-linked glycoproteins including IgE, our results indicate the propensity of garlic lectins to non-specifically activate mast cells and basophils in atopics as a result of higher density of IgE.…”

“…Atopic and non-atopic subjects were identified based on case history (atopic subjects chosen at random who had clinical symptoms of at least one allergic condition among the following: allergic rhinitis, asthma, and food allergy) of the subjects and SPT results with commercial extracts of house dust mite, and pollens [27,28]. The following allergenic extracts were used for SPT for confirming the allergic status: grass pollen mix 1, grass pollen mix 2, house dust mite and weed pollen mix.…”

TH2 adjuvants: Implications for food allergy

“…108 Of potential relevance to food allergy, several authors have reported that plant lectins may act as superallergens by binding IgE glycans and inducing cross-linking. 109,110 In addition, Lavelle et al 111 have reported that a number of plant lectins have mucosal adjuvant activity when administered orally. Finkelman 112 has reported that an undefined low-molecular-weight constituent of peanut extract can directly induce an anaphylactoid response in a complement-dependent manner, although whether this biological activity may also be important for innate immune activation and contribute to T H 2 polarization has not been reported.…”

Immunostimulatory properties of the major protein from the stem of the Ayurvedic medicinal herb, guduchi (Tinospora cordifolia)

“…Hemagglutination assay was performed according to the procedure of Burger (1974) using rabbit or human erythrocytes as described earlier (Pramod and Venkatesh, 2006;Pramod et al, 2007). Guduchi stem extract was prepared as described in Section 2.3; sample containing 20 mg protein in 3 mL was loaded on a column of Sephadex G-50 (1.8 cm × 157 cm) pre-equilibrated with phosphate-buffered saline (PBS), and elution was carried out using PBS at a flow rate of 12.5 mL/h.…”