title: Identifying Epithelial Endocytotic Mechanisms of the Peanut Allergens Ara h 1 and Ara h 2.
abstract: BACKGROUND
  Peanuts are still one of the highest contributors to anaphylactic deaths after ingestion of a food allergen. At the molecular level, interactions between peanut allergens and the intestinal epithelium are largely unexplored. Previous findings by our research group demonstrated that the major peanut allergens, i.e., Ara h 1, Ara h 2, Ara h 3, and Ara h 6, were able to cross the Caco-2 human cell culture model of the intestinal epithelium. This research broadened our investigation to identify the mechanisms by which the Caco-2 monolayers uptake peanut allergens, specifically by endocytosis. Here, we aim to increase our understanding of allergen-epithelial interactions and, more broadly, the pathway from allergen to allergy.
  
  
  METHODS
  The human Caco-2 cell culture model was exposed to peanut extract and a combination of confocal microscopy and inhibition studies were used to identify the endocytotic mechanisms of peanut allergens in intestinal epithelia.
  
  
  RESULTS
  Our findings demonstrate that the peanut allergens Ara h 1 and Ara h 2 are transported through intestinal epithelia initially via early endosomes using multiple endocytotic mechanisms. From there, they are then transported to late endosomes and ultimately to lysosomes.
  
  
  CONCLUSIONS
  These novel findings provide insight into the allergen-epithelial interactions of peanut allergens with the intestinal epithelium. Consequently, this opens the possibility of the use of these endocytotic pathways as targets for inhibitors in therapeutic development and preventative measures for peanut allergy in the future.
authors.affiliation: Centre for Cellular and Molecular Biology (CCMB), School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia.
authors.forename: Dwan
authors.initials: D
authors.lastname: Price
authors.forename: M Leigh
authors.initials: ML
authors.lastname: Ackland
authors.forename: Cenk
authors.initials: C
authors.lastname: Suphioglu
mesh_terms: D055516:2S Albumins, Plant / Q000378:metabolism*; D052179:Antigens, Plant / Q000276:immunology / Q000378:metabolism*; D018938:Caco-2 Cells; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000648:ultrastructure; D008247:Lysosomes / Q000378:metabolism*; D008565:Membrane Proteins; D018613:Microscopy, Confocal; D021183:Peanut Hypersensitivity / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology / Q000378:metabolism*
chemical_list: D055516:2S Albumins, Plant; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; C500890:Ara h 2 allergen, Arachis hypogaea; D006023:Glycoproteins; D008565:Membrane Proteins; D010940:Plant Proteins