Walnut allergen

Walnut allergens are a group of proteins found in the seeds of the walnut tree, primarily Juglans regia (English walnut) and Juglans nigra (Black walnut), that are responsible for triggering IgE-mediated allergic reactions in sensitized individuals [2, 4]. These allergens belong to several distinct protein families, including seed storage proteins such as 2S albumins (Jug r 1), 7S vicilins (Jug r 2, Jug r 6), and 11S legumins (Jug r 4), as well as non-specific lipid transfer proteins (Jug r 3) and profilins (Jug r 5, Jug r 7) [3, 14]. Their biological functions in the plant include nutrient storage for embryo development, lipid transport, and defense against environmental stress or pathogens [6, 11]. In humans, these proteins act as potent antigens that induce the production of allergen-specific IgE antibodies; upon re-exposure, the cross-linking of these antibodies on mast cells and basophils triggers the release of inflammatory mediators [4, 7]. This immune response can lead to clinical symptoms ranging from mild oral allergy syndrome to life-threatening anaphylaxis [2, 6]. While there are currently no approved drugs that directly bind to and neutralize the allergen proteins themselves, therapeutic management involves the use of epinephrine for acute reactions and anti-IgE therapies like omalizumab to increase the threshold of reactivity [10, 20]. Additionally, walnut allergenic extracts are utilized in oral immunotherapy (OIT) to induce clinical desensitization and improve tolerance in allergic individuals [8, 10].

Other names

Jug r 1Jug r 2Jug r 3Jug r 4Jug r 5Jug r 6Jug r 7Jug r 8Jug n 1Jug n 2English walnut allergenBlack walnut allergenPersian walnut allergenJuglans regia allergen

Adrenergic receptor agonism; IgE neutralization; IL-4/IL-13 signaling inhibition; Allergen-specific immunotherapy