title: Heterogeneous responses and cross reactivity between the major peanut allergens Ara h 1, 2,3 and 6 in a mouse model for peanut allergy.
abstract: BACKGROUND
  The relative contribution and the relation between individual peanut allergens in peanut allergic responses is still matter of debate. We determined the individual contribution of peanut proteins to B, T cell and allergic effector responses in a mouse model for peanut allergy.
  
  
  METHODS
  Mice were immunized and challenged by oral gavage with peanut protein extract or isolated allergens Ara h 1, 2, 3 and 6 followed by assessment of food allergic manifestations. In addition, T cell responses to the individual proteins were measured by an in vitro dendritic cell-T cell assay.
  
  
  RESULTS
  Sensitization with the individual peanut proteins elicited IgE responses with specificity to the allergen used as expected. However, cross reactivity among Ara h 1, 2, 3 and 6 was observed. T cell re-stimulations with peanut extract and individual peanut proteins also showed cross reactivity between Ara h 1, 2, 3 and 6. Despite the cross reactivity at the IgE level, only Ara h 2 and 6 were able to elicit mast cell degranulation after an oral challenge. However, after systemic challenge, Ara h 1, 2 and 6 and to lesser extent Ara h 3 were able to elicit anaphylactic responses.
  
  
  CONCLUSIONS
  Ara h 1, 2, 3 and 6 sensitize via the intra-gastric route, but differ in their capacity to cause allergic effector responses. Interestingly, extensive cross reactivity at T cell and antibody level is observed among Ara h 1, 2, 3 and 6, which may have important implications for the diagnosis and therapy of peanut allergy. Awareness about the relative contribution of individual peanut allergens and cross reactivity between these allergens is of importance for current research in diagnostics and therapeutics for and the mechanism of peanut allergy.
authors: Immunotoxicology group, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands ; Utrecht Centre for Food Allergy, Utrecht, The Netherlands.
authors: Joost J
authors: JJ
authors: Smit
authors: Utrecht Centre for Food Allergy, Utrecht, The Netherlands ; Utrecht University Medical Center, Utrecht, The Netherlands ; Current affiliation: HU University of Applied Sciences, Utrecht, The Netherlands.
authors: Maarten T
authors: MT
authors: Pennings
authors: Immunotoxicology group, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors: Karina
authors: K
authors: Willemsen
authors: Immunotoxicology group, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors: Manon
authors: M
authors: van Roest
authors: Utrecht University Medical Center, Utrecht, The Netherlands ; Current affiliation: NIZO food research BV, Ede, The Netherlands.
authors: Els
authors: E
authors: van Hoffen
authors: Immunotoxicology group, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors: Raymond H
authors: RH
authors: Pieters
keywords: Anaphylaxis; Cross-reactivity; IgE; Mouse model; Peanut allergy; Peanut proteins; Sensitization; T cell