Identification of the factors required for the survival niche of B cell memory.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K16283
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49070:Immunology-related
• Research Institution: Osaka University
• Principal Investigator: Koike Takuya 大阪大学, 感染症総合教育研究拠点, 特別研究員 (PD) (10855456)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 免疫記憶 / 記憶B細胞 / 長寿命形質細胞

Outline of Final Research Achievements

Immune memory involving B cells consists of memory B cells and long-lived plasma cells, but the mechanism of long-term survival of these cells remains unclear. We found that BAFF is important for the long-term survival of memory B cells. Since there were no molecular markers that could identify long-lived plasma cells, we generated a plasma cell time-stamping mouse system to discriminate long-lived plasma cells based on survival time. Using this system, we found that only small population of the plasma cells that entered the bone marrow enter B220lo MHC-IIlo long-lived plasma cell pool. Furthermore, the short-lived plasma cells were motile and migratory in the bone marrow, while the long-lived plasma cells were immobilized. These observations suggest that plasma cells behavior in BM is dynamically altered during their differentiation to B220loMHC-IIlo long lived plasma cells and that strength or stability of con- tact with the BM niche might be associated with PC longevity.

Free Research Field

免疫学

Academic Significance and Societal Importance of the Research Achievements

長寿命形質細胞の判別方法を明確にし、その形成機構について重要な観察を示した。この知見は長寿命形質細胞の生存機構のより詳細な解析を可能し、長年不明であった免疫記憶の維持機構を解明する手助けになる。これにより、長期に継続するワクチンの開発の一助となると考えられる。