Phleum pratense allergen Phl p 6 (Phl p 6) (Phl p 6)

Phleum pratense allergen Phl p 6 (Phl p 6) is a major protein allergen found in the pollen of Timothy grass, which is a significant contributor to seasonal allergic rhinitis and asthma worldwide (UniProt P43215). This small, highly soluble protein belongs to the group 5/6 allergen family and is characterized by its potent ability to cross-link IgE antibodies on the surface of mast cells and basophils, triggering the release of inflammatory mediators (WHO/IUIS Allergen Nomenclature). Structurally, Phl p 6 often exhibits cross-reactivity with other group 5 and 6 allergens from related grass species, making it a critical component in component-resolved diagnostics (CRD) to identify genuine grass pollen sensitization (PubMed: 10474032, PubMed: 22405072). Therapeutically, Phl p 6 is a primary component of allergen-specific immunotherapy (AIT) products, such as Grazax and Oralair, which aim to reprogram the immune system toward tolerance (FDA: STN 125444). These treatments work by inducing regulatory T cells and shifting the antibody profile from IgE to IgG4, thereby reducing the severity of allergic symptoms upon natural exposure (PubMed: 28214151). Successful clinical outcomes are associated with a significant reduction in allergic inflammation and a decreased reliance on symptomatic medications.

Other names

Timothy grass pollen allergen Phl p 6Major pollen allergen Phl p 6Pollen allergen Phl p VIPhl p 6.0101

Allergen-specific immunotherapy (AIT) induces immune tolerance by promoting the expansion of regulatory T cells (Tregs), shifting the Th2-biased response toward a Th1 response, and stimulating the production of allergen-specific IgG4 antibodies that compete with IgE for allergen binding (PubMed: 28214151).