2023 Fiscal Year Final Research Report

Dynamic in vivo fluorescence imaging analysis of Immunocytes relevant to salivary IgA production.

Research Project

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Project/Area Number	20H03902
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 57080:Social dentistry-related
Research Institution	The University of Tokushima
Principal Investigator	KATAOKA Kosuke 徳島大学, 大学院医歯薬学研究部(歯学域), 教授 (50283792)
Co-Investigator(Kenkyū-buntansha)	土居貴士大阪歯科大学, 歯学部, 准教授 (20388375) 河村佳穂里大阪歯科大学, 歯学部, 講師 (20737019) 戸村道夫大阪大谷大学, 薬学部, 教授 (30314321) 三宅達郎大阪歯科大学, 歯学部, 教授 (40200141) 楠本豊大阪大谷大学, 薬学部, 准教授 (40252689)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	NALT / 樹状細胞
Outline of Final Research Achievements	This nasal vaccine with a novel nasal adjuvant strongly induces salivary IgA antibodies by activating dendritic cells in the immune-inducing tissue NALT (nasopharynx-associated lymphoid tissue; equivalent to the human Waldeyer's pharyngeal ring (tonsil)) located at the base of the nasal cavity. After nasal administration of this intranasal vaccine, a widespread accumulation of dendritic cells behind the NALT 1/5 (closer to the laryngeal region) was observed, indicating tissue specificity. B cells stimulated by NALT dendritic cells were also IgA class switching in the submandibular glands as well as in the NALT. NALT-derived B cells were also found to be more abundant in the sublingual glands than in the submandibular and parotid glands. Furthermore, mouse NALT B cells treated with this nasal vaccine showed strong chemokine receptor CCR9 gene expression.
Free Research Field	予防歯科学・口腔衛生学・粘膜免疫学
Academic Significance and Societal Importance of the Research Achievements	口腔免疫防御システムの中心的ツールと考えられる唾液抗原特異的IgA抗体は、その産生メカニズムはほとんど知られていない。免疫誘導組織NALTから免疫実効組織唾液腺までの免疫担当細胞の詳細な動態と細胞間クロストークメカニズムを明らかにすることにより、唾液分泌型IgA抗体を効果的に産生する経鼻ワクチンの開発に繋げることが本研究の目標である。細菌やウイルスの多くが口腔・鼻腔からの侵入・感染で始まることから、唾液IgA抗体を効率的に誘導・産生することは、効果的な防御法となる。つまり、重症化予防のためのワクチンではなく、感染予防のため経鼻・経口型粘膜ワクチン開発は喫緊の課題に対する解決法となる。