Cha o 3, a cypress pollen allergen, does not activate basophils in Japanese cypress pollinosis

Yoshiaki Kobayashi; Keisuke Suzuki; Minoru Tateno; Yuki Nakamura; Kayoko Ishimaru; Yuka Nagasaka; Daiju Sakurai; Katsuyo Ohashi-Doi; Atsuhito Nakao

doi:10.1016/j.jacig.2023.100198

Cha o 3, a cypress pollen allergen, does not activate basophils in Japanese cypress pollinosis

J Allergy Clin Immunol Glob. 2023 Dec 1;3(1):100198. doi: 10.1016/j.jacig.2023.100198. eCollection 2024 Feb.

Authors

Affiliations

¹ Department of Immunology, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
² Torii Pharmaceutical Co, Ltd, Tokyo, Japan.
³ Department of Otorhinolaryngology, Head and Neck Surgery, University of Yamanashi, Yamanashi, Japan.
⁴ Yamanashi GLIA Center, University of Yamanashi, Yamanashi, Japan.
⁵ Atopy Research Center, Juntendo University School of Medicine, Tokyo, Japan.

Abstract

Background: In Japan, pollinosis caused by the Japanese cypress (JCy) Chamaecyparis obtusa is among the very common seasonal allergies. In JCy pollinosis, Cha o 1 is the first major allergen, and Cha o 2 is the second major allergen. Recently, Cha o 3 was identified as a new JCy pollen allergen in JCy pollinosis. However, the relative contribution of Cha o 3 to JCy pollinosis compared with that of Cha o 1 and that of Cha o 2 has not been fully elucidated.

Objective: This study aimed to clarify the allergenicity of Cha o 3 compared with that of Cha o 1 and Cha o 2 in JCy pollinosis.

Methods: We recruited 27 patients with JCy pollinosis and performed the basophil activation test (BAT) with native (n) Cha o 1, Cha o 2, and Cha o 3 purified from JCy pollen. In addition, we a performed JCy-specific IgE suppression test.

Results: In the BAT, 26 of 27 patients (96%) and 18 of 27 patients (67%) showed positive basophil activation in response to n Cha o 1 and n Cha o 2, respectively, as judged by CD203c expression. Little CD203c expression in response to n Cha o 3 was seen. The presence of n Cha o 3 marginally reduced the titer levels of JCy-specific IgE.

Conclusion: Cha o 3 showed little ability to activate basophils and suppress JCy-specific IgE titers compared with Cha o 1 or Cha o 2 in patients with JCy pollinosis. Thus, Cha o 3 may not be a major allergen in JCy pollinosis.

Keywords: Cha o 3; Japanese cypress pollinosis; basophil activation test.