Analysis of mucosal tolerance by regulatory T cell in chronic otitis media

• Project/Area Number: 16K11187
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Oita University
• Principal Investigator: Hirano Takashi 大分大学, 医学部, 講師 (20305056)
• Co-Investigator(Kenkyū-buntansha): 川野 利明 大分大学, 医学部, 助教 (30633424) ; 鈴木 正志 大分大学, 医学部, 教授 (60211314)
• Research Collaborator: SUZUKI MASASHI 大分大学, 医学部, 教授 (60211314) ; KAWANO TOSHIAKI 大分大学, 医学部, 助教 (30633424)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 制御性T細胞 / 粘膜免疫 / 免疫寛容 / B細胞 / 鼻粘膜 / 脾臓 / Bリンパ球 / 頸部リンパ節 / インフルエンザ菌 / 制御性T細胞細胞 / ヘルパーT細胞 / サイトカイン / 慢性中耳炎

Outline of Final Research Achievements

We investigated the effect of regulatory T cell (Treg) on B cell immune responses against outer membrane protein (OMP) from NTHi in vitro. Mice were vaccinated intranasally with OMP , and mononuclear cells (MNCs) were collected from the nasal mucosa, Tregs and helper T cells (Th) were isolated from the spleens of those mice. Three different cell culture groups were allocated: MNCs co-cultured with Tregs, or with Th cells, and MNCs cultured alone, respectively. At 24 and 72 hours after cell culture, cytokine levels were determined by ELISA. CD69 or CD80 expressions on B2 cells were detected by flow cytometryic analysis. IL-10 levels were significantly higher in Treg and Th groups than in the control group. The ratio of CD80+B220+ B2 cells was higher in the control group than in the Treg and Th groups during incubation. Tregs and Th cells may partially inhibit B cell functions, such as T cell activation. These inhibitory effects may be related to IL-10.

Academic Significance and Societal Importance of the Research Achievements

マウス慢性中耳炎由来の制御性T細胞を用いた検討は試料サイズが少ないため、脾臓由来の制御性T細胞やhelper T細胞によるマウス鼻粘膜由来B細胞における影響について検討を行った。現在まで、上気道粘膜由来B細胞におけるT細胞の関与についてin vitroでの解析の報告は少なく、今回は慢性感染と制御性T細胞の関与が上気道においても起こりえる可能性が示唆され、制御性T細胞のB細胞における抗体産生能に与える直接的な抑制効果よりも、特にT-B細胞間の相互作用の抑制効果が上気道粘膜における免疫寛容に関わっていることが示唆された。制御性T細胞は、慢性気道感染における新しい治療標的になるかもしれない。

Research Products

• [Journal Article] Interaction between regulatory T cells and antibody producing B cells for the immune responses at the upper respiratory mucosae against nontypeable Haemophilus influenza-in vitro assay model- (2019)
  • Author(s): Hirano T., Kadowaki Y., Matsunaga T., Yoshinaga K., Kawano T., Moriyama M., Suzuki M.
  • Journal Title: Annals of Otology, Rhinology and Laryngology Volume: in press
  • Peer Reviewed
• [Journal Article] Monophosphoryl lipid A enhances nontypeable Haemophilus influenzae-specific mucosal and systemic immune responses by intranasal immunization (2017)
  • Author(s): Taro Iwasaki, Takashi Hirano, Satoru Kodama, Yoshinori Kadowaki, Munehito Moriyama, Toshiaki Kawano, Masashi Suzuki
  • Journal Title: International Journal of Pediatric Otorhinolaryngology Volume: 97 Pages: 5-12
  • DOI: 10.1016/j.ijporl.2017.03.018
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] 経鼻粘膜免疫後の頸部リンパ節に対する制御性T細胞が与える影響 (2018)
  • Author(s): 平野 隆，川野利明，松永崇志，門脇嘉宣、児玉 悟、鈴木正志
  • Organizer: 日本耳鼻咽喉科免疫アレルギー学会
• [Presentation] 経鼻粘膜免疫後の頸部リンパ節に対する制御性T細胞が与える影響 (2018)
  • Author(s): 平野 隆、川野利明、松永崇志、門脇嘉宣、児玉 悟、鈴木正志
  • Organizer: 日本耳鼻咽喉科免疫アレルギー学会
• [Presentation] 慢性中耳炎における制御性T細胞免疫寛容機序に対するin vitroでの解析 (2017)
  • Author(s): 平野 隆、川野利明、松永崇志、門脇嘉宣、児玉 悟、鈴木正志
  • Organizer: 日本耳科学会