Ambrosia artemisiifolia pollen allergens (Amb a)

Ambrosia artemisiifolia pollen allergens, particularly the major allergen Amb a 1, are the primary environmental triggers for late-summer seasonal allergic rhinitis (hay fever) and allergic asthma (PubMed: 22673357). Amb a 1 is a pectate lyase protein that cross-links allergen-specific IgE antibodies on the surface of mast cells and basophils, leading to the rapid release of inflammatory mediators such as histamine and leukotrienes (UniProt: P00813; NCBI: PMC3604471). While the allergens themselves are the causative agents of disease, they are used therapeutically in allergen-specific immunotherapy (AIT), such as the FDA-approved sublingual tablet Ragwitek (FDA: STN 125447). The goal of such therapy is to re-educate the immune system toward a state of tolerance by inducing regulatory T cells and shifting the cytokine profile away from the allergic Th2 response (JACI: 10.1016/j.jaci.2013.06.007). Because these treatments involve direct exposure to the allergen, they carry a significant risk of localized and systemic allergic reactions, including anaphylaxis (PubMed: 24703901). The name provided in the query refers to a biological process and clinical indication rather than a specific molecular target like a receptor or enzyme.

Other names

Short ragweed pollen allergensCommon ragweed pollen allergensAmb a 1Amb a allergensAmbrosia artemisiifolia pollen allergen extract

Allergen-specific immunotherapy (AIT) involves the repeated administration of allergens to induce peripheral T-cell tolerance, increase the population of regulatory T cells (Tregs), and shift the immune response from a Th2-biased allergic profile to a Th1-mediated profile, leading to the production of allergen-specific IgG4 'blocking' antibodies (PubMed: 23910688; JACI: 10.1016/j.jaci.2013.06.007).