Major allergen Amb a 1 (Amb a 1)

Amb a 1 is the primary major allergen identified in the pollen of Ambrosia artemisiifolia (short ragweed), recognized by over 90% of ragweed-sensitized individuals (UniProt: P13347). Structurally, it is a pectate lyase enzyme that facilitates pollen tube growth by degrading pectin in the plant cell wall (PMID: 25413333). In humans, Amb a 1 acts as a potent immunogen that triggers type I hypersensitivity reactions, leading to symptoms of allergic rhinitis and asthma (WHO/IUIS). As a therapeutic target, it is the central component of allergen-specific immunotherapy (AIT), such as the sublingual tablet Ragwitek (FDA). These therapies aim to desensitize the patient by shifting the immune response from a Th2-dominated profile to one characterized by regulatory T-cell activity and the production of protective IgG4 antibodies.

Other names

Antigen EPectate lyaseAmb a IShort ragweed allergen Amb a 1Amb a 1.01

Allergen-specific immunotherapy (AIT) involves the controlled administration of the Amb a 1 allergen to induce peripheral T-cell tolerance and promote the synthesis of allergen-specific IgG4 antibodies, which neutralize the allergen and prevent IgE-mediated mast cell degranulation.