Research Abstract |
T helper type 1 (Th1) and Th2 cells, resulting from antigenic stimulation in the presence of interleukin (IL)-12 and IL-4, respectively, are implicated in the pathology of diseases including allergic and autoimmune diseases. Txk/Rlk is a member of Tec family tyrosine kinases. We have reported that Txk acts as a Th1 cell specific transcription factor in the T lymphocytes. We found that Txk expression was affected positively by IL-12, IL-18 and IFN-g and negatively by IL-4 and IL-13. We next studied whether administration of txk expression plasmid induced expression of Txk in their spleen cells. The spleen cells from the mice administered txk expression plasmid produced more IFN-gamma as compared with those from mice administered control plasmid in an antigen specific manner. IL-2 and IL-4 secretion of the spleen cells were comparable between the two mouse groups. Txk administration did not reduce serum IgG concentration. However, it markedly reduced serum total IgE level and an IgG1/IfG2a ration, reflection of Th1/Th2 balance. Furthermore, txk administration reduced the antigen specific IgE levels in sera of the mice, which was used for immunizing mice. Thus, Txk enhances IFN-g secretion and thus modulates Th1/Th2 cytokine balance, leading to reduction of serum IgE in an antigen specific manner in vivo.
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