Reduced anaphylactic potential of denatured pullulan-conjugated Cry j 1

• Published in: International immunopharmacology 2021-10, Vol.99, p.108026-108026, Article 108026
• Main Authors: Utsumi, Daichi, Sugawara, Takeru, Hashida, Kosumo, Yasuhara, Yuki, Fujinami, Koji, Lund, Kaare, Ohashi-Doi, Katsuyo
• Format: Article
• Language: English
• Subjects: Allergens; Allergens - immunology; Allergic rhinitis; Allergies; Allergy immunotherapy; Anaphylaxis; Animals; Antigens, Plant - administration & dosage; Antigens, Plant - chemistry; Antigens, Plant - immunology; Antihistamines; Binding; Cell activation; Conjugation; Cry j 1 antigen; Cryptomeria - immunology; Denaturation; Desensitization, Immunologic - methods; Disease Models, Animal; Enzyme-linked immunosorbent assay; Glucans - administration & dosage; Glucans - chemistry; Glucans - immunology; Humans; Hypersensitivity; Hypoallergen; Immunoglobulin E; Immunological tolerance; Immunotherapy; Japanese cedar pollen; Mast Cells - immunology; Mice; Passive Cutaneous Anaphylaxis; Plant Proteins - administration & dosage; Plant Proteins - chemistry; Plant Proteins - immunology; Pollen; Pollen - immunology; Pollinosis; Polysaccharides; Pullulan; Quality of life; Rats; Reduction; Rhinitis; Rhinitis, Allergic, Seasonal - blood; Rhinitis, Allergic, Seasonal - diagnosis; Rhinitis, Allergic, Seasonal - immunology; Rhinitis, Allergic, Seasonal - therapy; Subcutaneously immunotherapy
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2021.108026

•Denatured pullulan-conjugated Cry j 1 (Dn p-Cry j 1) possessed reduced anaphylactic potential.•The reduced anaphylactic potential compared to native Cry j 1 (n Cry j 1) was achieved by two-step process.•Dn p-Cry j 1 is proposed as a candidate for next-generation Japanese cedar allergy immunotherapy. Japanese Cedar (JC) pollinosis is the most common seasonal allergic rhinitis in Japan. Throughout the JC pollen season, patients suffer from the allergic symptoms, resulting in a reduction of quality of life. Allergy immunotherapy (AIT) is an established treatment option for a wide range of allergens that unlike symptomatic treatments (e.g. antihistamines) may provide sustained immune tolerance. However, AIT, especially subcutaneous immunotherapy (SCIT) has a fatal anaphylaxis risk due to the use of crude allergen extracts. Consequently, development of allergen derivatives with substantially reduced anaphylactic potential is desirable. An allergen derivative that showed reduced IgE-binding and anaphylactic potential was developed through conjugation of native Cry j 1 (n Cry j 1), a major JC allergen, to the polysaccharide pullulan followed by chemical but non-covalent denaturation. The resulting Cry j 1 allergen derivative, Dn p-Cry j 1, showed reduced IgE-binding and IgE-mediated effector cell activation in vitro using an ELISA competition assay and a mast cell activation model (EXiLE). Reduced anaphylactic potential of Dn p-Cry j 1 in vivo was demonstrated using the rat passive cutaneous anaphylaxis (PCA) assay. The difference in anaphylactic potential of Dn p-Cry j 1 compared to n Cry j 1 in wild-type rats was of the same magnitude as the difference seen in the anaphylaxis reactions obtained with n Cry j 1 in wild-type rats and mast-cell deficient rats, indicating a dramatic reduction in anaphylactic potential of Dn p-Cry j 1. These results indicate that Dn p-Cry j 1 is a promising candidate for next-generation JC AIT.