1. Pollen shells and soluble factors play non-redundant roles in the development of allergic conjunctivitis in mice
- Author
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Keiko Maeda, Hideoki Ogawa, Yusuke Sone, Ko Okumura, Nobuyuki Ebihara, Mayuki Kojima, Tomoaki Ando, Toshiaki Shimizu, Jiro Kitaura, Kumi Izawa, Meiko Kimura, Moe Matsuzawa, Ayako Kaitani, Nobuhiro Nakano, Anna Kamei, Saaya Fukase, Akira Murakami, and Makoto Nishiyama
- Subjects
Mice, Inbred BALB C ,Conjunctiva ,biology ,Chemistry ,Allergens ,Eosinophil ,medicine.disease_cause ,medicine.disease ,Allergic conjunctivitis ,Interleukin 33 ,Mice ,Ophthalmology ,medicine.anatomical_structure ,Immune system ,Pollen ,Immunology ,otorhinolaryngologic diseases ,medicine ,biology.protein ,Animals ,Antibody ,Sensitization ,Conjunctivitis, Allergic - Abstract
Purpose We aimed to clarify the role of particulate allergen exposure to the conjunctiva in the development of allergic conjunctivitis. Methods We administered ragweed pollen suspension, pollen extract, pollen shell, particulate air pollutants, and their combinations to the mouse conjunctiva five days a week without prior sensitization. Clinical signs were scored. Histological changes, cellular infiltrations, mRNA expressions, lymph node cell recall responses, and serum immunoglobulin levels were assessed. Immune cell-depleting antibodies and ST2 knockout mice were used to investigate the cellular and molecular requirements. Results Pollen suspension, but not the extract or shell alone, induced robust eosinophilic conjunctivitis, accompanied by a proliferative response of epithelial cells. A combination of pollen extract and shell completely restored eosinophil accumulation. In addition, eosinophilic conjunctivitis was induced by a mixture of particulate air pollutants and pollen extract. Mechanistically, eosinophil accumulation was ameliorated by deficiency of the IL-33 receptor ST2 and abolished by depleting CD4+ T cells. Pollen shells, but not the extract, induced IL-33 release from conjunctival epithelial cells in vivo. Conclusions Our results indicate the non-redundant roles for the allergens’ particulate properties and soluble factors in the development of allergic conjunctivitis.
- Published
- 2021