Strategy of Salmonella persistent infection based on suppression of bone-marrow derived immune cells induced by secreted proteins

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K07102
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 49050:Bacteriology-related
• Research Institution: Chiba University
• Principal Investigator: Takaya Akiko 千葉大学, 大学院薬学研究院, 准教授 (80334217)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: サルモネラ / 持続感染 / 免疫抑制 / 骨髄系細胞 / 病原因子 / 分泌タンパク質

Outline of Final Research Achievements

In this study, we found the novel mechanism that Salmonella has an ability to suppress humoral immunity via secretion of the virulence factor, SiiE Our result suggested that SiiE inhibits the interaction between the integrin β1 on plasma cells and laminin β1 on stromal cells in bone marrow. Furthermore, our study was also suggested that accumulation of immature myeloid cells provide a balance of immunosuppressive and protective functions in the host response to the persistent infection with Salmonella. Taking these findings together, it is suggested that Salmonella could maintain persistent infection by suppressing the host immune response in various strategies.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

病原細菌の持続感染では宿主に特異的な記憶免疫が形成されることから、弱毒化ワクチンなどに応用される。今回の成果は、ある種の弱毒化ワクチンなどでは宿主の持つ長期記憶等の免疫応答を低下させる可能性を示唆している。従って、弱毒化ワクチンなどの利用において他の抗体変化を調べることで安全性や効果について検討することの重要性を示唆している。一方、骨髄の長命形質細胞を特異的に阻害する戦略により免疫疾患の治療などへの応用に発展する可能性も考えられる。