title: Oral immunotherapy induces local protective mechanisms in the gastrointestinal mucosa.
abstract: BACKGROUND
  Oral immunotherapy (OIT) is a promising treatment for food allergy. Studies are needed to elucidate mechanisms of clinical protection and to identify safer and potentially more efficacious methods for desensitizing patients to food allergens.
  
  
  OBJECTIVE
  We established a mouse model of OIT to determine how the dose or form of antigen may affect desensitization and to identify mechanisms of desensitization.
  
  
  METHODS
  Increasing doses of egg white or ovomucoid as OIT were administered orally to sensitized mice. The impact of OIT on anaphylaxis elicited by oral allergen challenge was determined. Allergen-specific antibody and cytokine responses and mast cell and basophil activation in response to OIT were measured. Gene expression in the small intestine was studied by microarray and real-time PCR.
  
  
  RESULTS
  OIT resulted in desensitization but not tolerance of mice to the allergen. OIT did not result in desensitization of systemic effector cells, and protection was localized to the gastrointestinal tract. OIT was associated with significant changes in gene expression in the jejunum, including genes expressed by intestinal epithelial cells. Extensively heated ovomucoid that does not trigger anaphylaxis when given orally to sensitized mice was as efficacious as native ovomucoid in desensitizing mice.
  
  
  CONCLUSIONS
  OIT results in clinical protection against food-induced anaphylaxis through a novel mechanism that is localized to the intestinal mucosa and is associated with significant changes in small intestinal gene expression. Extensively heating egg allergen decreases allergenicity and increases safety while still retaining the ability to induce effective desensitization.
authors.affiliation: Division of Pediatric Allergy and Immunology, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Leonard
authors.forename: Gustavo
authors.initials: G
authors.lastname: Martos
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Anna
authors.initials: A
authors.lastname: Nowak-Węgrzyn
authors.forename: M Cecilia
authors.initials: MC
authors.lastname: Berin
mesh_terms: D000284:Administration, Oral; D000485:Allergens / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D000707:Anaphylaxis / Q000517:prevention & control / Q000628:therapy; D000818:Animals; D016207:Cytokines / Q000276:immunology; D003888:Desensitization, Immunologic; D004195:Disease Models, Animal; D004529:Egg White / Q000009:adverse effects; D000939:Epitopes / Q000276:immunology; D005260:Female; D005512:Food Hypersensitivity / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D005753:Gastric Mucosa / Q000276:immunology* / Q000378:metabolism; D020869:Gene Expression Profiling; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D010059:Ovomucin / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D011489:Protein Denaturation
chemical_list: D000485:Allergens; D016207:Cytokines; D000939:Epitopes; D007070:Immunoglobulin A; D010059:Ovomucin; D007073:Immunoglobulin E