Immediate hypersensitivity reactions to peanuts, an IgE-mediated food allergy, has been a major public health concern for many years, particularly in westernized countries where peanut allergies can persist into adulthood. For allergic patients, avoidance currently remains the only viable option (1).
Eleven potentially important peanut allergens have been identified. Ara h1, Ara h2, Ara h3, and Ara h6 have been designated the major peanut allergens. Ara h2 and Ara h6, two highly related 2S albumins, especially contribute to the development of allergic reactions (2).
Mouse peanut allergy models have been used to study the pathogenesis of the peanut allergy and to help develop new treatments. The mouse models can be induced by administration of crude peanut extract (CPE) or each purified Ara allergen and evaluated for the humoral immune responses such as serum anti-IgE and IgG antibodies against the allergen, T-cell mediated immune response associated cytokines levels, as well as body temperature and clinical signs of anaphylaxis. These factor changes observed in the disease models are useful for studying the efficacy of protective effects against the development of allergic reactions (3–9).
To evaluate the humoral immune response against CPE in the mouse allergy models, Chondrex, Inc. provides ELISA kits for assaying mouse anti-CPE subtype and subclass antibodies.
Mouse Anti-Crude Peanut Extract (CPE) Antibody Assay Kits
|Product||Catalog #||Price (USD)|
|Mouse Anti-Crude Peanut Extract (CPE) IgA Antibody Assay Kit||3061||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgE Antibody Assay Kit||3063||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgG Antibody Assay Kit||3056||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgG1 Antibody Assay Kit||3057||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgG2a Antibody Assay Kit||3058||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgG2b Antibody Assay Kit||3059||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgG3 Antibody Assay Kit||3060||392.00|
|Mouse Anti-Crude Peanut Extract (CPE) IgM Antibody Assay Kit||3062||392.00|
What Are Peanut Allergens?
Ara h1, a glycoprotein, belongs to the vicilin (7S) family of seed storage proteins and forms a stable 150-kDa trimer. Its internal IgE-binding regions demonstrate the relatively weak activity of native-form Ara h 1 (trimer) and the strong binding of IgE to denatured monomers (63 kDa on immunoblots) when cross-linking IgE (10).
Ara h2 belongs to the conglutin family of seed storage proteins that is related to the 2S albumin family. Ara h2 contains ten independent IgE-binding linear epitopes. Two isoforms, Ara h 2.01 and Ara h 2.02, were identified respectively as a 17 and 19-kDa doublet on SDS-PAGE. The larger isoform, containing twelve extra amino acids including a duplication of a strong IgE-binding sequence, DPYSPS, can bind more IgE antibodies. (11).
Ara h3, a peanut glycinin, belongs to the legumin (11S) family of seed storage proteins and consists of a 360–380-kDa protein constructed from 60 kDa monomers. Ara h3 contains three IgE-binding epitopes in the 14, 42, and 45 kDa fragments.(12)
Ara h6 has a molecular weight of 14.5 kDa which is 59 % homologous to Ara h2. It also possesses heat and digestion stability, a protease-stable core, and allergenic potency similar to that of Ara h2 (13, 14).
Food Allergies in Humans
An IgE-mediated food allergy can manifest as inflammation of the skin, gut, and/or lung, and is a major public health concern in many countries. The incidence of food allergy in the United States ranges from 1 to 2% in adults and 6 to 8% in children. The most severe cases (0.003%) can result in anaphylactic shock and death. Eight foods are responsible for more than 90% of food allergies: cow’s milk, eggs, soy, wheat, peanuts, tree nuts (walnuts, hazelnuts, almonds, cashews, pecans, and pistachios), fish, and shellfish (Figure 1).
Among these allergens, the allergenicity of the peanut (whether it is raw or roasted) is the highest relative to other food allergens such as egg (OVA) and milk (casein). Therefore, peanut allergies account for most of the severe food-related allergic reactions to present early in life. The allergy does not usually resolve in highly sensitized people, especially in cases of immediate hypersensitivity reactions which can persist into adulthood. For allergic patients, avoidance currently remains the only viable option (1)(15).
Timeline of Mouse Peanut Allergy Models and Evaluation Methods
Mouse peanut allergy models have been used to study the pathogenesis of the peanut allergy and develop new treatments. The following are published protocols to develop peanut allergy mouse models. The models are induced by oral administration of CPE, followed by CPE challenges and recommended markers to evaluate the disease severity (3–9).