Banana lectin (BanLec) induces non-specific activation of basophils and mast cells in atopic subjects

Eur Ann Allergy Clin Immunol. 2018 Nov;50(6):243-253. doi: 10.23822/EurAnnACI.1764-1489.64. Epub 2018 Jul 24.

Abstract

Dietary lectins play a major role in the activation of mast cells / basophils by bridging cell surface IgE glycans to release histamine and other mediators. In the present study, the effect of mannose / glucose-specific banana lectin (BanLec) on the activation of mast cells / basophils from non-atopic and atopic subjects has been investigated. BanLec was purified from banana pulp in a yield of 7 mg/kg. Leukocytes isolated from heparinized blood of non-atopic / atopic subjects were used for quantitation of the released histamine. Approximately 28.2% of the atopics (n = 117) was positive by skin prick test (SPT) to purified BanLec (100 µg/mL concentration), and all the non-atopics (n = 20) were negative. Maximal release of histamine was seen at 2 µg of BanLec. In percent histamine release, an increase of 35-40% is observed in case of atopics (n = 7) compared to non-atopics (n = 5), and the histamine release from atopic and non-atopic subjects correlates fairly well with the total serum IgE levels (R2 = 0.817). BanLec also induces release of histamine (26.7%) from mast cells present in rat peritoneal exudate cells. BanLec can significantly activate and degranulate mast cells and basophils by cross-linking the trimannosidic core mannose of IgE glycans in atopic population as compared to non-atopic population; the activation is marginal in the case of non-atopics.

Keywords: atopics; banana lectin; histamine release; serum IgE; skin prick test.

MeSH terms

  • Adult
  • Allergens / immunology
  • Animals
  • Basophils / immunology*
  • Female
  • Histamine / blood
  • Histamine / metabolism
  • Histamine Release / immunology*
  • Humans
  • Hypersensitivity, Immediate / immunology
  • Immunoglobulin E / immunology
  • Male
  • Mast Cells / immunology*
  • Middle Aged
  • Musa / chemistry
  • Musa / immunology*
  • Plant Lectins / immunology*
  • Plant Proteins, Dietary / immunology*
  • Rats, Wistar
  • Skin Tests
  • Young Adult

Substances

  • Allergens
  • Plant Lectins
  • Plant Proteins, Dietary
  • Immunoglobulin E
  • Histamine