Objective : This study was carried out for the purpose of knowing the effect from T-cell activation of the C57BLb mouse by the extraction from a EtoAc fraction of LJE.
Methods : There are two-signal T-cell activation paradigm, the first signal induced by T cell receptor(TCR) engagement determines the antigen specificity, whereas the second costimulatory signal determin es the activation threshold and the functional outcome of the antigen--specific activation. The activation threshold is modulated by costimulatory signals, and their dysregulation may play a critical role in the activation of autoreactive T cells. And, CD80/CD%-CD28/CTLA-4 is the most important and best-studied costimulatory pathway. CD80 and CD86 molecules are expressed on activated antigen-presenting cells(A Pcs) and bind to their ligands CD28 and CTLA-4 on T cells.
Results :
1. In the proliferous effect of thymus T cells, water extracts of EtoAc fraction of ELC played an important role on the proliferating thymus T cells compared with control group.
2. EtoAc fraction of ELC promoted the CDW(B7-1) and Thl cytokines especially IFN--V, II-2, IL-10, TGF-0 gene expression, but decreased CTLA-4, CD28 and Th2 cytokines IL-4 gene expression.
3. EtoAc fraction of ELC up-regulates CD44´CD69´CDE´, CD4´CD25´, CD8´CD25´, CD3´CD80´ expression but not CD3´CDB´ by anti-CD3-stimulated T cells.
4. Binding activity of transcription factors(NF-KB, NFAT, AF-1) was increased by EtoAc Fraction of ELC. We thought that EtoAc Fraction of ELC also could regulate the expression of a variety of inducible genes by increasing the binding activity of transcription factors(NF-KB, NFAT. AP-1).
Conclusions : Above results indicates that EtoAc fraction of ELC play an important role in the activation of autoreactive T cells by promoting Th 1 cytokinesUFN-v, IL-2) and decreasing CTLA-4, CD28 and Th2 cytokines IL-4 gene expression, through up-regulating cell surface molecule(CD80, CD25, CD44, CD69). Therefore further deep studies shoud be accomplished about its effects on T-cell activation.
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