Phleum pratense allergen 12 (Profilin-1) (Phl p 12)

Phleum pratense allergen 12, widely known as Phl p 12, is a profilin protein derived from Timothy grass (Phleum pratense) pollen. Profilins are small, ubiquitous, and highly conserved proteins that play a critical role in regulating the actin cytoskeleton by binding to monomeric actin and poly-L-proline sequences (Source: UniProt P35079). In clinical allergology, Phl p 12 is classified as a pan-allergen because its high structural homology across various plant species leads to extensive cross-reactivity between grass pollens, tree pollens, and plant-derived foods. While often considered a minor allergen in terms of primary sensitization, it is a frequent cause of polysensitization and oral allergy syndrome in patients with hay fever (Source: PMID: 10851150). Therapeutic intervention involving Phl p 12 typically occurs through allergen-specific immunotherapy (AIT), where controlled exposure to the allergen aims to desensitize the patient's immune system and reduce the severity of allergic rhinitis and asthma symptoms (Source: PMID: 24943127).

Other names

Profilin-1Timothy grass profilinPhl p 12.0101

Induction of immune tolerance through the recruitment of regulatory T cells (Tregs), shifting the immune response from a Th2 to a Th1 profile, and stimulating the production of allergen-specific IgG4 blocking antibodies (Source: PMID: 21664142, PMID: 28923135).