Mechanisms for effective humoral memory against variant viruses

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H01028
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 49:Pathology, infection/immunology, and related fields
• Research Institution: Osaka University
• Principal Investigator: Tomohiro Kurosaki 大阪大学, 免疫学フロンティア研究センター, 特任教授(常勤) (50178125)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 液性免疫記憶 / メモリーB細胞 / 中和抗体 / ウイルス感染

Outline of Final Research Achievements

Our results do not support the previous concept that high affinity B cells are selected into memory B cell compartment after virus infection. Rather, low to intermediate affinity B cells were indeed selected into this compartment. Because such low/intermediate affinity memory B cells are not so much committed to the primarily infected viruses, some of the memory B cells are still capable of being activated by secondary infection of variant viruses. Among the memory B cells possessing cross-reactivity for the variant viruses, the most high affinity memory B cells were get activated, making plasma cells and subsequent neutralizing antibodies against variant viruses.

Free Research Field

免疫学　感染症学

Academic Significance and Societal Importance of the Research Achievements

インフルエンザウイルス、HIVウイルス等、変異ウイルスに対しても防御活性を有するワクチン開発が待望されている。本研究で得られた結果はワクチン後にも、獲得された血清の質・量のみならず、メモリーB細胞の質・量が変異ウイルス感染時に重要な役割を担っていることが判明し、従来の血清タイターの測定のみでは、ワクチンの能力、特に変異ウイルス感染時における能力の検定には不十分であることが判明した。