INTERFERON SIGNALING IN T CELLS

干扰素(IFN)是具有抗增殖、抗病毒作用的细胞因子 以及增强免疫的生物学特性。干扰素诱导转录 早期反应基因，由激活的 Jak/Stat途径。在T细胞中，外周血淋巴细胞的孵育 或带有干扰素α的Jurkat细胞(一种人源性T细胞白血病)诱导T细胞 细胞受体(TCR)信号成分：蛋白酪氨酸磷酸酶 CD45和蛋白酪氨酸激酶Lck和ZAP-70快速关联 干扰素受体的阿尔法链(IFNαR1)。对以下方面的要求 这些TCR信号转导酶在IFNpha介导的 研究了JAK/STAT信号通路、抗增殖和抗病毒作用 在缺乏这些蛋白质的Jurkat细胞中。INFAlpha--刺激 JAK/STAT途径和抗病毒活性在缺失细胞中是完整的 CD45、LCK或ZAP-70的抗增殖作用受到影响，但 当细胞与这些蛋白质重组时可以恢复。这些 研究结果表明，干扰素α通过以下途径发挥抗增殖作用 激活T细胞中利用组分的新信号通路 TCR信号级联。需要检验的假设是 除了JAK/STAT途径外，IFNpha还激活了一个不同的信号 T细胞中需要蛋白质酪氨酸磷酸酶和蛋白质的级联反应 酪氨酸激酶被TCR用来驱动抗增殖活性。 为了证明这一假设，编码CD45、ZAP-70的cDNA构建 或在结构基序中包含点突变或缺失的Lck 对这些蛋白质的功能至关重要的基因将被表达出来 在缺乏这两种蛋白质的Jurkat细胞中。这将使我们能够 确定这些蛋白质中需要结合到的结构域 并确定这些结构域的生物学意义 抑制干扰素α诱导抗增殖作用的能力 表达这些结构的细胞。这些信号的意义 未转化的原代T细胞中的蛋白质将通过 缺乏这些的基因工程小鼠的胸腺细胞 蛋白质。此外，需要JAK/STAT途径参与 在激活此信令网络时将使用CELL进行检查 缺乏JAK1、TYK2、Stat 1和Stat 2蛋白的品系。

Interferons (IFNs) are cytokines that have anti-proliferative, anti-viral and immunoenhancing biological properties. IFNs induce the transcription of early responsive genes which are regulated by the activation of the Jak/Stat pathway. In T cells, incubation of peripheral blood lymphocytes or Jurkat cells (a human derived T-cell leukemia) with IFNalpha induces T cell receptor (TCR) signaling components: protein tyrosine phosphatase CD45 and protein tyrosine kinases Lck and ZAP-70 to rapidly associate with the alpha chain of the IFN receptor (IFNalpha R1). The requirement for these TCR signaling enzymes in IFNalpha-mediated activation of the JAK/Stat pathway, anti-proliferative and anti-viral effects were studied in Jurkat cells lacking these proteins. INFalpha-stimulation of the Jak/Stat pathway and anti-viral activity were intact in cells deficient in CD45, Lck or ZAP-70 whereas the anti-proliferative effect was affected but could be restored when cells were reconstituted with these proteins. These findings demonstrate that IFNalpha exerts in anti-proliferative effect by activating a novel signaling pathway in T cells which utilizes components of the TCR signaling cascade. The hypothesis to be tested will be that besides the Jak/Stat pathway, IFNalpha activates a different signaling cascade in T cells that requires protein tyrosine phosphatases and protein tyrosine kinases used by the TCR to drive the anti-proliferative activity. In order to prove this hypothesis, cDNA constructs encoding CD45, ZAP-70 or Lck that contain point mutations or deletions in structural motifs which are essential for the function of these proteins will be expressed in Jurkat cells that lack these proteins respectively. This will allow us to identify domains in these proteins that are required for binding to IFNalpha R1 and determine the biological significance of these domains to inhibit the ability IFNalpha to induce an anti-proliferative effect in cells expressing these constructs. The significance of these signaling proteins in non-transformed primary T cells will be examined using thymocytes from genetically engineered mice which are lacking these proteins. In addition, requirement for the Jak/Stat pathway to participate in the activation of this signaling network will be examined using cell lines that are deficient in Jak1, tyk2, Stat 1 and Stat 2 proteins.