Identifying a novel self-reactive T cell subpopulation and its functional significance

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K16272
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49070:Immunology-related
• Research Institution: Tohoku University
• Principal Investigator: Kawabe Takeshi 東北大学, 医学系研究科, 准教授 (50834652)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: CD4 T細胞 / 恒常性 / 感染免疫 / 自己免疫疾患

Outline of Final Research Achievements

CD4 T lymphocytes are essential for useful adaptive immune responses. Among CD4 T cells, we have recently identified a subpopulation with a memory phenotype that arises from naive precursors dependently of self antigen recognition and can exert innate immune function in infectious conditions. Based on this finding, this study aimed to define markers for this subpopulation and unravel its host-protective as well as autoimmune functions. In this study, we identified three markers that specify MP versus foreign antigen-specific memory cells. Moreover, we found that MP cells contain a Th1-like “MP1" subset and this subpopulation can exert innate effector function. Furthermore, we are obtaining evidence arguing that MP cells can induce systemic inflammation in certain circumstances. Together our results suggest MP cells as a unique CD4 T cell subpopulation possessing innate effector function as well as autoimmune potential.

Free Research Field

免疫学

Academic Significance and Societal Importance of the Research Achievements

従来、T細胞は外来抗原特異的獲得免疫応答にのみ寄与するものとされてきたが、本研究により、その一部の細胞集団「MP細胞」が自然免疫的様式にて感染防御に寄与することが明らかになった。本研究成果は、従来の古典的T細胞免疫学の理解に一石を投じるものである。今後、MP細胞の自然免疫機能や炎症惹起能を細胞・分子レベルで解明することにより、新規抗感染症治療戦略の提唱や自己免疫・炎症性疾患に対する根治的治療法の創出にも結び付くものと期待される。