| Project/Area Number |
11670976
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Hematology
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TANAKA Junji Hokkaido Univ., Grd. School of Med., Associate Prof., 大学院・医学研究科, 助教授 (50250452)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | GVHD / GVL / KIR / Monocyte / Seem cell transplantation |
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| Research Abstract |
Although granulocyte colony-stimulating factor (G-CSF)-mobillized peripheral blood mononuclear cells (G-PBMC) grafts contain at least ten times more T cells than standard bone marrow grafts, the incidence and severity of acute graft-versus-host disease (aGVHD) is not higher than that observed with allogeneic marrow. We have shown that the induction of constimulatory molecule CD28 responsive complex in CD4+ cells appears to be suppressed by the presence of CD14+ cells in the G-PBMC
It has recently been shown that inhibitory natural killer cell receptors (NKRs) on NK cells negatively regulate NK cell and also T cell functions through their binding to MHC class I molecules. A CD94/NKG2 heterodimer serves as a receptor for HLA-E non-classical HLA-I molecules. We showed the expression of CD94/NKG2A on T cells was higher in cGVHD patients with good response to conventional immunosuppressive therapy than in cGVHD patients with poor response. Also, we reported the increased expression of CD94/NKG2A on CD8+ T cells in G-PBMC after mixed lymphocyte culture (MLC). However, CD94/NKG2A expression did not increase when CD14-depleted G-PBMC was used. The addition of purified CD14+ cells to CD14-depleted G-PBMC induced CD94/NKG2A expression in a dose-dependent fashion, however, this enhancing effect of purified CD14+ cells on CD94/NKG2A expression was inhibited by the presence of a membrane between responder cells and CD14+ cells. Therefor, CD14+ cells in G-PBMC induce CD94/NKG2A expression on CD8+ T cells, which in turn appear to down-regulate alloresponses. Therefore, inhibitory NKR expression on T cells has an important role in the regulation of alloresponse.
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