Timothy grass allergen Phl p 5 (Phl p 5)

Timothy grass allergen Phl p 5 is a major protein allergen from Phleum pratense, recognized as a primary driver of seasonal allergic rhinitis and asthma (UniProt P14946). It belongs to the Group 5 grass pollen allergens and is characterized by its high IgE-binding capacity and potent T-cell stimulatory properties (PubMed: 20584546). In the context of sublingual immunotherapy (SLIT), Phl p 5 is resorbed through the oral mucosa and captured by oral mucosal Langerhans cells (oLCs), which play a pivotal role in allergen recognition and the induction of immune tolerance (Allam et al., 2010). This recognition pathway is essential for the migration of oLCs to regional lymph nodes, where they promote the differentiation of regulatory T cells and attenuate Th2-mediated allergic responses (J Allergy Clin Immunol. 2010). Therapeutic interventions targeting this pathway primarily involve allergen-specific immunotherapy using standardized extracts like Grastek or Oralair to induce clinical desensitization (FDA Label). Additionally, the interaction between Phl p 5 and its specific IgE can be modulated by anti-IgE therapies such as Omalizumab, which prevent the activation of effector cells like mast cells and basophils (Xolair Prescribing Information). Monitoring of Phl p 5-specific IgE and IgG4 levels serves as a key biomarker for diagnosing sensitivity and assessing the efficacy of immunotherapy (ThermoFisher Scientific).

Other names

Phl p VGroup 5 allergen of Phleum pratenseTimothy grass pollen allergen 5Major pollen allergen Phl p 5

Allergen-specific immunotherapy induces immune tolerance by shifting the T-cell response from a Th2 to a Th1/Treg profile and increasing the production of allergen-specific IgG4 antibodies.