Allergenicity and Immunomodulatory Effect of a Depigmented-Polymerized Peanut Extract Tested in a Mouse Model of Peanut Allergy

The availability of animal models has allowed the investigation of different forms of immunotherapy. This study aims to investigate the allergenicity of a depigmented-polymerized peanut allergen extract in a mouse model of peanut allergy. Four weeks-old CH3/HeOUJ female mice were divided in four groups of eight mice. Mice were orally sensitized with native extract (NE) (10 mg) or depigmented-polymerized extract (PE) (10 mg), 9 times at weekly intervals. At week 9 animals were orally challenged (100 mg of NE or 100 mg of PE). Serum samples were collected at 0, 30 and 45 days. Rectal temperature was measured every 10 minutes after challenge and the clinical score recorded. • Group 1: sensitized with NE and challenged with NE • Group 2: sensitized with NE and challenged with PE • Group 3: sensitized with PE and challenged with NE • Group 4: sensitized with PE and challenged with PE Mice sensitized with NE showed high titers of peanut-specific IgG1 and IgE after sensitizations, significantly higher (p<0.05) than in mice sensitized with PE. After antigen challenges, Group 1 developed severe reactions while in Group 2, anaphylactic reactions were largely less severe than in Group 1. Group 3 developed severe anaphylactic reactions while in Group 4, 75% of animals did have significant symptoms. The body temperature correlated with the symptom score. Sensitization with PE induced lower levels of antigen-specific antibodies. Moreover, mice challenged with PE experienced less clinical symptoms than NE indicating than depigmented-polymerized extracts are significantly less allergenic.