Novo modelo murino de alergia alimentar ao amendoim

Abstract

The prevalence of food allergy has increased in the last two decades. Egg, milk and peanut are the main foods related to this disease. Peanut allergy differs from egg and milk allergy in terms of severity and rates of desensitization, which suggests that each type of food allergy has its own singularities. Thus, the research group from the Immunobiology Laboratory (LIB) and collaborators have developed standardized models of food allergy to study the different types of this disease. There are currently standardized models of food allergy to two antigens: ovalbumin, from eggs, and beta- lactoglobulin from milk. In order to complete the top three food allergies, this study aimed to standardize a model of food allergy to peanut according to the laboratory standards in order to allow comparative studies. Firstly, the optimal dose of sensitization to peanut protein extract (PPE) was tested in BALB/c mice. On day 0, mice were immunized with 8g, 40g or 80g of PPE in 3mg of aluminium hydroxide (Al(OH)3). After 14 days, the mice received the same doses of PPE without Al(OH)3. After 7 days, the mice were orally challenged by drinking peanut extract for 14 days. As a result, sensitization with 8g and 40g of PPE led to a higher production of anti-PPE IgG than the highest dose (80g). Furthermore, sensitization with 40g of PPE led to weight loss and alterations in the eating patterns of allergic mice. Thus, 40g of PPE was chosen as the dose of sensitization in the following experiments. Next, the new peanut allergy model was tested in C57BL/6 mice. BALB/c and C57BL/6 mice were immunized twice with 40g of PPE in 3mg of Al(OH)3 and challenged with peanut extract. Although C57BL/6 mice was more responsive to the immunization with PPE than BALB/c mice, the protocol worked in both strains. This was evidenced by an increase in the production of total IgE and anti-PPE IgG, as well as by inflammatory alterations in the small intestine. Lastly, the allergic mice underwent a preference test in order to investigate the aversion phenomenon. The allergic and control groups of both strains preferred drinking peanut extract over water, with no difference in the amount of peanut extract ingestion between groups. This suggests there is no aversion in the current model of peanut allergy. Thus, this study was able to standardize a new model of peanut allergy according to the standards of our laboratory.