Development and Characterization of an Effective Food Allergy Model in Brown Norway Rats

Abstract

BackgroundFood allergy (FA) is an adverse health effect produced by the exposure to a given food. Currently, there is no optimal animal model of FA for the screening of immunotherapies or for testing the allergenicity of new foods.ObjectiveThe aim of the present study was to develop an effective and rapid model of FA in Brown Norway rats. In order to establish biomarkers of FA in rat, we compared the immune response and the anaphylactic shock obtained in this model with those achieved with only intraperitoneal immunization.MethodsRats received an intraperitoneal injection of ovalbumin (OVA) with alum and toxin from Bordetella pertussis, and 14 days later, OVA by oral route daily for three weeks (FA group). A group of rats receiving only the i.p. injection (IP group) were also tested. Serum anti-OVA IgE, IgG1, IgG2a, IgG2b and IgA antibodies were quantified throughout the study. After an oral challenge, body temperature, intestinal permeability, motor activity, and mast cell protease II (RMCP-II) levels were determined. At the end of the study, anti-OVA intestinal IgA, spleen cytokine production, lymphocyte composition of Peyer’s patches and mesenteric lymph nodes, and gene expression in the small intestine were quantified.ResultsSerum OVA-specific IgG1, IgG2a and IgG2b concentrations rose with the i.p. immunization but were highly augmented after the oral OVA administration. Anti-OVA IgE increased twofold during the first week of oral OVA gavage. The anaphylaxis in both IP and FA groups decreased body temperature and motor activity, whereas intestinal permeability increased. Interestingly, the FA group showed a much higher RMCP II serum protein and intestinal mRNA expression.ConclusionsThese results show both an effective and relatively rapid model of FA assessed by means of specific antibody titres and the high production of RMCP-II and its intestinal gene expression.

Effect of a cocoa-enriched diet on immune response and anaphylaxis in a food allergy model in Brown Norway rats

“…1). The FA induction was performed as previously described [18]. Briefly, rats received i.p.50 g of ovalbumin (OVA, grade V, Sigma-Aldrich, Madrid, Spain) as allergen, 2.5 mg of alum (Imject®; Pierce, IL, USA) and 50 ng of toxin from Bordetella pertussis (tBp; Sigma-Aldrich) as adjuvants.…”

“…To assess intestinal permeability, βLG was quantified in serum obtained during AR by ELISA as previously reported [18].…”

“…From the middle of the small intestine, a piece (0.5 cm) was kept in RNA later ® (Ambion, Life Technologies, Austin, USA) until gene expression analysis and another little piece was separated for histology. Gut washes were obtained from the distal half of the small intestine for quantification of total and specific IgA [18].…”

Identificação de proteínas IgE- reativas do camarão sete-barbas (Xiphopenaeus kroyeri)

“…A -Carne do camarão e B -casca do camarão. Marcador de massa molecular (MM), extrato da carne do camarão (CM), extrato da casca do camarão (CS) e indivíduos não alérgicos (19)(20)(21)(22)(23)(24)(25)(26)(27) A alergia alimentar tem se tornado um problema crescente de saúde pública em muitos países e pode ser desencadeada por qualquer alimento. Em crianças os alimentos considerados mais alergênicos são leite de vaca e ovo e em adultos há uma alta frequência de alergia a frutos do mar, sendo camarão o marisco considerado mais alergênico.…”

“…A alergia alimentar é descrita como um efeito adverso para a saúde decorrente de uma resposta imune específica que ocorre de forma reprodutível após exposição a um determinado alimento 19 , normalmente desencadeada por uma proteína nele presente. Outra proteína considerada um alérgeno major para camarão é a arginina quinase.…”