2006 Fiscal Year Final Research Report Summary
The differences of immunological responses of human T cells among thymocytes, cord blood and adult peripheral blood
| Project/Area Number |
16590372
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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 |
Bacteriology (including Mycology)
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| Research Institution | Tokyo Women's Medical University |
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Principal Investigator |
FUJIMAKI Wakae Tokyo Women's Medical University, School of Medicine, Lecture Instructor, 医学部, 助手 (90256496)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIYAMA Takehiko Tokyo Women's Medical University, School of Medicine, Professor, 医学部, 教授 (00050550)
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| Project Period (FY) |
2004 – 2006
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| Keywords | human T cells / post-thymic muturation / regulatory T cells / FOXP3 / CD45 isoform / human thymic cells / human cord blood |
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| Research Abstract |
Human T cells show different biological responses according to T-cell maturation or subset when stimulated with conventional antigen or bacterial superantigens. CD25^+CD4^+ regulatory T cells (Treg) suppress T cell activation in vitro and regulate multiple immune reactions in vivo. To explore the developmental process of Treg, we investigated the functional differences of Treg from thymocytes (Thy), cord blood (CB) and adult peripheral blood (APB). CB Treg showed weak suppressive activity compared to Treg from Thy or APB, being mostly CD45RA^+. Meanwhile, FOXP3 protein expression, typically upregulated in Treg, was weak. In contrast, Treg from Thy or APB displayed strong suppressive activity. Most of APB Treg exhibited a CD45RA^- phenotype with a minor population being CD45RA^+. CD45RA^+ APB Treg had features that were between those of CD45RA^- APB Treg and CB Treg, and were thought to eventually mature to CD45RA^- Treg. Thymic Treg contained both CD45RA^+ and CD45RA^- subsets, with both expressing the FOXP3 protein. Although CB Treg showed weak suppressive activity, expanded Treg had enhanced suppressive activity associated with increased FOXP3 expression. These results hence indicate that Treg suppressive function is down-regulated following departure from the thymus and is subsequently restored in response to acquired stimulation after birth, with an associated change in the CD45 isoform. Meanwhile, the default function seen in CB Treg may be important in the rejection of the fetus at delivery.
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Research Products
(26 results)
