MODIFIED PAR-J-I ALLERGEN FROM P-JUDAICA POLLEN AND ITS RATE OF ABSORPTION IN RATS

Polymerized allergens (allergoids) have been introduced in the immunot herapy of allergic disease in order to reduce the risk of side effects . However, their high molecular weight can be a limit, particularly wh en they are administered by a route involving passage through the muco sal barrier. We describe a simple procedure aimed at developing an ori ginal modified allergen with significantly less allergenic potential ( intended as human IgE-binding capacity) but preserving the monomeric n ature of the molecule. Par j I, the major allergen of Parietaria judai ca pollen, was purified by a combination of monoclonal antibodies and affinity chromatography. Par j I allergen was then modified by reactio n with potassium cyanate (KCNO), and compared with the native allergen to evaluate its allergenic potency (RAST-inhibition) and molecular we ight (SDS-PAGE). Modified allergen showed significantly lower allergen ic potency but kept its original molecular weight, making it particula rly suitable for buccal (sublingual) administration. To study the adso rption profile, modified Par j I was radiolabeled and administered int ravenously and sublingually to normal rats. The prospects for clinical application of the modified allergen are discussed.