| Co-Investigator(Kenkyū-buntansha) |
FUJIMAKI wakae Tokyo Women's Medical University School of Medicine, Lecture Instructor, 医学部, 講師 (90256496)
IMANISHI Kenichi Tokyo Women's Medical University School of Medicine, Associate Professor, 医学部, 助教授 (80124527)
UCHIYAMA Takehiko Tokyo Women's Medical University School of Medicine, Professor, 医学部, 教授 (00050550)
TANAKA Yoshimasa Tokyo Women's Medical University School of Medicine, Research Associate, 医学部, 助手 (90280700)
KATO Hidehito Tokyo Women's Medical University School of Medicien ,Research Associate, 医学部, 助手 (00241084)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1997: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
We examined the expression of the H4 T cell activation marker in thymic T cell subpopulations, and found that TCR-αβィイD1+ィエD1CD4ィイD1+ィエD1 thymic T cells are segregated into three subpopulations based upon H4 levels. Thymic T cells with either no or low H4 expression differentiate via the mainstream differentiation pathway in the thymus. H4ィイD1intィエD1 thymic T cells, which express a skewed Vβrepertoire of Vβ2, 7 and 8 in their TCRs, show the phenotype of NKT cells : CD44ィイD1highィエD1, Ly6CィイD1highィエD1, NK1.1ィイD1+ィエD1 and TCR-αβィイD1lowィエD1. H4ィイD1highィエD1 thymic T cells also show a skewed Vβ repertoire, Vβ2, 7 and 8, and predominantly express an invariant Vα14-Jα281ィイD1+ィエD1α chain in their TCRs, but constitute a distinct population in that they are CD44ィイD1intィエD1, Ly6CィイD1-ィエD1, NK1.1ィイD1-ィエD1 and TCR-αβィイD1highィエD1. Thus, invariant Vα14ィイD1+ィエD1 thymic T cells consist of ordinary NKT cells and a new type of T cell population. Vβ7ィイD1+ィエD1 and Vβ8.1ィイD1+ィエD1 invariant Vα14ィイD1+ィエD1 thymic T cells are present in DBS/2 mice, which carry mammary tumor virus-7-encoded superantigens, in comparable levels to those in BALB/c mice, indicating that invariant Vα14ィイD1+ィエD1 thymic T cells escape negative selection in the thymus. Furthermore,Vβ7ィイD1+ィエD1 invariant Vα14ィイD1+ィエD1 thymic T cells in DBA/2 mice are in the immunologically responcilve state, and a superantigen, Yersinia pseudotuberculosis-derived mitogen (YPM)-induced Vβ7ィイD1+ィエD1 invariant Vα14ィイD1+ィエD1 thymic T cell blasts from DBA/2 and BALB/c mice exhibited equally enhanced responses upon restimulation with YPM. Thus, invariant Vα14ィイD1+ィエD1 thymic T cells that escape negative selection in DBA/2 mice contain T cells as functionally mature as those in BALB/c mice.
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