Identification of the deficiency of CD4+CD25+ T regulatory cells in New Zealand Black mice

• Main Authors: Ya-Ken Chen, 陳雅肯
• Other Authors: Chia-Rui Shen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/74023416330370561431

碩士 === 長庚大學 === 醫學生物技術研究所 === 95 === New Zealand Black (NZB) mice spontaneously develop autoimmune hemolytic anemia (AIHA). The major target of the pathogenic red blood cell (RBC) autoantibodies is the anion channel protein Band 3, and CD4 T cells from NZB mice also respond to Band 3. Previous studies from our laboratories showed that Band 3 peptide 861-874 contains a dominant autoreactive helper T-cell epitope with the ability in vivo to modulate the course of AIHA in NZB mice. We have recently found that after inhaling this peptide, the proportion of CD4+CD25+ cells, which are recognized as regulatory T cells were promoted. Adoptive transfer of BLAB/c CD4+CD25+ cells can significantly reduce their RBC bound autoantibody levels. Therefore, in this study, I aim to characterize the CD4+CD25+ regulatory T cells in NZB AIHA development and generate the gene-engineered Foxp3-expressing regulatory cells in vitro. First, we have demonstrated that much lower frequency of regulatory T cells was found in NZB mice as compared to the age-matched BALB/c animals. Second, the expression of Foxp3, the potential marker of T regulatory cells, was reduced in these NZB CD4+CD25+ cells. Most importantly, these CD4+CD25+ cells in NZB mice seemed to lose the suppressive effects on cell proliferation and cytokine production, whereas the CD4+CD25+ cells isolated from BALB/c mice were able to abolish the cell proliferation in response to CD3 stimulation. Finally, the Foxp3-high expressing vector has been constructed and transfected into primary mouse T cells by nucleofection. After transfection with Foxp3, the Foxp3 gene-engineered cells were anergic to anti-CD3/CD28 in vitro. Further studies will test if these gene-engineered regulatory T cells are able to suppress autoimmune diseases.