Grass pollen allergens (Group 1 and Group 5) (GPA)

Grass pollen allergens, specifically those belonging to Group 1 (e.g., Phl p 1) and Group 5 (e.g., Phl p 5), are the primary drivers of seasonal allergic rhinitis and asthma in sensitized individuals globally. Group 1 allergens are beta-expansins that facilitate pollen tube penetration by loosening the plant cell wall, while Group 5 allergens are highly potent proteins unique to the Pooideae grass subfamily (Source: UniProt P43213, Q40240). These proteins act as antigens that cross-link IgE antibodies on the surface of mast cells and basophils, triggering the release of histamine and other inflammatory mediators. In the context of drug development, these allergens are the active components in allergen-specific immunotherapy (AIT) products. By exposing the patient to controlled, increasing doses of these allergens, the immune system is reprogrammed to favor regulatory T-cell activity and the production of protective IgG4 antibodies, thereby reducing clinical symptoms and the need for symptomatic medication (Source: PMID: 31141331).

Other names

Timothy grass pollen allergensRye grass pollen allergensPhl p 1Phl p 5Lol p 1Lol p 5Pooideae pollen allergensBeta-expansins (Group 1)Grass pollen major allergens

Allergen-specific immunotherapy (AIT) involves the repeated administration of specific allergens to induce immunological tolerance. This process shifts the immune response from a Th2-dominated profile to a Th1 and regulatory T-cell (Treg) response, leading to the production of blocking antibodies such as IgG4 and IgA, which prevent IgE-mediated mast cell degranulation (Source: PMID: 28024484, NIH).