| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2003: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
MKP-M, a JNK-specific MAP kinase phosphates, is weakly expressed in naive CD4+ T cells. The MKP-M expression level decreased in Th1-differentiation condition, whereas it increased in Th-2 differentiation condition in vitro, indicating MKP-M may be involved in Th1/Th2 differentiation. Last year, using the adenoviral overexpression system, we showed that exogenous MKP-M expression in CD4+ T cells significantly enhances Th2-type differentiation. Our research results for this year are the followings :
1)We introduced both will-type(WT) and dominant negative (CS)-forms of MKP-M cDNA controlled by T cell-specific Lck promoter into fertilized eggs of C57BL/6, and established T cell-specific transgenic mice. In some MKP-M CS transgenic mice, in which exogenous MKP-M expression level was high, intra-thymic T cell differentiation was blocked at the CD4+CD8+ double positive cell stage. We analyzed transgenic mice, in which intra-thymic T cell differentiation was normal. CD4+ T cells were isolated and stimulated in vitro with anti-CD3 plus CD28 antibody under the conditions of Th1- or Th2-dominant conditions. In this in vitro differentiation experiment, CD4+ T cells from MKP-M WT transgenic mice showed significantly Th2-biased differentiation, whereas those from MKP-M CS transgenic mice showed Th1-biased differentiation.
2)MKP-M WT and CS T cell specific transgenic mice were immunized with ovalubumin(OVA) antigen. At day 14 after the immunization, OVA-specific Ig subtypes were measured in the blood. MKP-M WT transgenic mice showed Th2-biased OVA-specific immune responses (high IgE), whereas CS transgenic mice showed Th1-biased (high IgG2a) immune responses.
3)We generated chimeric mice out of MKP-M +/- mouse ES cells, which we established last year. We are currently working on the establishment of MKP-M-/- mouse strains.
4)We isolated mouse IL-12 receptor beta 1 gene promoter region. We determined the nucleotide sequences and performed promoter functional assays.
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