| Project/Area Number |
15390132
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Experimental pathology
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| Research Institution | National Institute for Longevity Sciences (2005)
Tokyo Metropolitan Institute of Gerontology (2003-2004) |
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Principal Investigator |
SHIMIZU Jun National Institute for Longevity Sciences, Section of Immunology, Department of Mechanism of Aging, Section Chief, (研究所)・老化機構研究部免疫研究室, 室長 (60291134)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2005: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2004: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2003: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Aging / CD4 T cells / Immunoregulation |
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| Research Abstract |
CD4^+CD25^+ T cells have immunoregulatory and suppressive functions, and are responsible for suppressing self-reactive cells and maintaining self-tolerance. In addition to CD4^+CD25^+ T cells, there is also some evidence that a fraction of CD4^+CD25^- T cells exhibit suppressive activity in vitro or in vivo. We have shown using aged mice that aging not only leads to a decline in the ability to mount CD4^+CD25^- T cell responses, but at the same time, renders aged CD4^+CD25^- T cells suppressive. Here we report two newly established mAbs, which could abrogate the suppressive function of aged CD4^+CD25^- T cells. These mAbs recognized the same protein, the transmembrane phosphatase CD45. Cross-linking of CD45 on aged CD4^+CD25^- T cells was required for the disruption of their suppressive activity. Surprisingly, these mAbs also abrogated the suppressive action of CD4^+CD25^+ T cells in vitro. Our results demonstrate an unexpected function of CD45 as a negative regulator neutralizing the suppressive activity of aged CD4^+CD25^- and young CD4^+CD25^+ T cells.
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