INTERFERON SIGNALING IN T CELLS

干扰素（IFN）是具有抗增殖、抗病毒和抗肿瘤活性的细胞因子。 和免疫增强生物学特性。干扰素诱导转录 早期反应基因的激活， Jak/Stat途径。在T细胞中，孵育外周血淋巴细胞 或Jurkat细胞（一种人源性T细胞白血病）与IFN α诱导T 细胞受体（TCR）信号传导组分：蛋白酪氨酸磷酸酶 CD 45和蛋白酪氨酸激酶Lck和ZAP-70迅速与 IFN受体的α链（IFN α R1）。的要求 这些TCR信号传导酶在IFN α介导的 研究JAK/Stat通路、抗增殖和抗病毒作用 在缺乏这些蛋白质的Jurkat细胞中。INFa刺激 Jak/Stat途径和抗病毒活性在缺乏免疫抑制剂的细胞中是完整的。 CD 45、Lck或ZAP-70，而抗增殖作用受到影响， 当细胞用这些蛋白质重组时，可以恢复。这些 研究结果表明，IFN α发挥抗增殖作用， 激活T细胞中的新信号通路， TCR信号级联反应。待检验的假设是， 除了Jak/Stat通路，IFN α还激活一种不同的信号传导， T细胞中的级联反应，需要蛋白酪氨酸磷酸酶和蛋白 TCR使用酪氨酸激酶来驱动抗增殖活性。 为了证明这一假设，构建了编码CD 45、ZAP-70 或在结构基序中含有点突变或缺失的Lck 对这些蛋白质的功能至关重要的蛋白质 在缺乏这些蛋白的Jurkat细胞中。这将使我们 来鉴定这些蛋白质中的结构域， IFN α R1，并确定这些结构域的生物学意义， 抑制IFNalpha诱导抗增殖作用的能力 表达这些构建体的细胞。这些信号的重要性 将使用以下方法检查未转化的原代T细胞中的蛋白质： 来自基因工程小鼠的胸腺细胞， proteins.此外，要求Jak/Stat途径参与 在这个信令网络的激活将使用细胞检查 缺乏Jak 1、tyk 2、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.