title: Dietary medium-chain triglycerides promote oral allergic sensitization and orally induced anaphylaxis to peanut protein in mice.
abstract: BACKGROUND
  The prevalence of peanut allergies is increasing. Peanuts and many other allergen sources contain significant amounts of triglycerides, which affect absorption of antigens but have unknown effects on sensitization and anaphylaxis. We recently reported that dietary medium-chain triglycerides (MCTs), which bypass mesenteric lymph and directly enter portal blood, reduce intestinal antigen absorption into blood compared with long-chain triglycerides (LCTs), which stimulate mesenteric lymph flow and are absorbed in chylomicrons through mesenteric lymph.
  
  
  OBJECTIVE
  We sought to test how dietary MCTs affect food allergy.
  
  
  METHODS
  C3H/HeJ mice were fed peanut butter protein in MCT, LCT (peanut oil), or LCT plus an inhibitor of chylomicron formation (Pluronic L81). Peanut-specific antibodies in plasma, responses of the mice to antigen challenges, and intestinal epithelial cytokine expression were subsequently measured.
  
  
  RESULTS
  MCT suppressed antigen absorption into blood but stimulated absorption into Peyer patches. A single gavage of peanut protein with MCT, as well as prolonged feeding in MCT-based diets, caused spontaneous allergic sensitization. MCT-sensitized mice experienced IgG-dependent anaphylaxis on systemic challenge and IgE-dependent anaphylaxis on oral challenge. MCT feeding stimulated jejunal-epithelial thymic stromal lymphopoietin, Il25, and Il33 expression compared with that seen after LCT feeding and promoted T(H)2 cytokine responses in splenocytes. Moreover, oral challenges of sensitized mice with antigen in MCT significantly aggravated anaphylaxis compared with challenges with the LCT. Importantly, the effects of MCTs could be mimicked by adding Pluronic L81 to LCTs, and in vitro assays indicated that chylomicrons prevent basophil activation.
  
  
  CONCLUSIONS
  Dietary MCTs promote allergic sensitization and anaphylaxis by affecting antigen absorption and availability and by stimulating T(H)2 responses.
authors.affiliation: Graduate Center for Nutritional Sciences and Internal Medicine Department, Division of Digestive Diseases and Nutrition, University of Kentucky, Lexington, Ky 40536-0200, USA.
authors.forename: Jianing
authors.initials: J
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Lihua
authors.initials: L
authors.lastname: Tang
authors.forename: Willem J S
authors.initials: WJ
authors.lastname: de Villiers
authors.forename: Donald
authors.initials: D
authors.lastname: Cohen
authors.forename: Jerold
authors.initials: J
authors.lastname: Woodward
authors.forename: Fred D
authors.initials: FD
authors.lastname: Finkelman
authors.forename: Erik R M
authors.initials: ER
authors.lastname: Eckhardt
mesh_terms: D000485:Allergens / Q000276:immunology; D000707:Anaphylaxis / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000941:Antigens / Q000276:immunology; D010367:Arachis / Q000737:chemistry / Q000276:immunology*; D001491:Basophils / Q000276:immunology / Q000378:metabolism; D002914:Chylomicrons / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D004032:Diet / Q000379:methods; D005260:Female; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007378:Interleukins / Q000276:immunology; D007408:Intestinal Absorption / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism; D007583:Jejunum / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D021183:Peanut Hypersensitivity / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D014280:Triglycerides / Q000008:administration & dosage / Q000276:immunology* / Q000378:metabolism
chemical_list: D000485:Allergens; D000906:Antibodies; D000941:Antigens; D002914:Chylomicrons; D016207:Cytokines; D007074:Immunoglobulin G; D007378:Interleukins; D014280:Triglycerides; D007073:Immunoglobulin E