timothy major allergens

Timothy major allergens refer to a purified preparation of the primary allergenic proteins found in Timothy grass (*Phleum pratense*) pollen, specifically Phl p 1 and Phl p 5 (historically designated as allergens 19 and 25). These proteins are utilized in allergen-specific immunotherapy (ASIT) to treat patients with grass pollen-induced allergic rhinitis (hay fever) and allergic asthma. The therapeutic approach involves the repeated subcutaneous administration of these allergens, often adsorbed to an adjuvant like aluminum hydroxide, to modulate the immune system. The mechanism of action includes the induction of peripheral T-cell tolerance (anergy), a shift from a Th2-biased to a Th1-biased immune response, and the stimulation of allergen-specific IgG4 antibodies. These IgG4 antibodies act as "blocking antibodies" that compete with IgE for allergen binding, thereby preventing the activation of mast cells and basophils and reducing allergic inflammation.

Other names

Phl p 1Phl p 5Timothy grass pollen major allergensPhleum pratense major allergensPurified grass pollen extracts