THE MECHANISMS OF INDUCTION OF TNF ALPHA GENE EXPRESSION VIA IA MOLECULES

急性移植物抗宿主病(GVHD)由供者T细胞引发 它们识别与MHC第二类(Ia)相关的宿主抗原 分子。最近的研究强烈表明，细胞因子，特别是 肿瘤坏死因子-α、白介素2和干扰素-γ在急性白血病中发挥重要作用 GVHD。最近，人们的注意力集中在肿瘤坏死因子-α在脑内的作用上。 急性移植物抗宿主病。血清肿瘤坏死因子-α水平在人类移植物抗宿主病、血液和 急性移植物抗宿主病患者皮肤细胞表达肿瘤坏死因子-α抗体 肿瘤坏死因子-α改善小鼠和人移植物抗宿主病及肿瘤坏死因子-α在体内的应用 老鼠会引起类似移植物抗宿主病的变化。我们假设订婚的 同种异体反应性供者T细胞对宿主细胞表面LA分子的影响 急性移植物抗宿主病患者肿瘤坏死因子-α释放的诱导物。微生物超抗原 与La分子结合的分子可能进一步促进肿瘤坏死因子-α的释放 来自La+单核细胞，来自激活的La+T细胞和角质形成细胞 出现在急性移植物抗宿主病。 明确肿瘤坏死因子-α基因表达的诱导机制 LA分子，我们将： 1.检测急性移植物抗宿主病(GVHD)中肿瘤坏死因子-α的诱导作用。我们将：a)评估 急性移植物抗宿主病患者肿瘤坏死因子-α的表达，b)检测 同种异体反应中单核细胞和T细胞中肿瘤坏死因子-α的诱导 检测超抗原对肿瘤坏死因子-α的诱导作用。 2.分析了LA耦合信号传感器的功能和结构 小路。我们将：a)研究La配体对PKC的激活，b) 检测参与PKC的磷脂酶和第二信使 激活，c)检查酪氨酸磷酸化的激活 通过La配体的途径，d)识别La相关分子。 3.确定参与其中的DNA反应元件和调节蛋白 通过1a转录激活肿瘤坏死因子-α。我们将研究：a) 用CAT技术研究La配体对肿瘤坏死因子-α基因的转录激活作用 分析和b)La诱导特异性核蛋白/DNA复合体 配基。 建议的研究应能更好地了解 急性移植物抗宿主病的发病机制及对LA的重要意义 免疫细胞和非免疫细胞中介导的信号转导 炎症性癌和癌组织中异常表达La的细胞 自身免疫力。

Acute graft versus host disease (GVHD) is initiated by donor T cells which recognize host antigens in association with MHC class II (Ia) molecules. Recent studies strongly suggest that cytokines, particularly TNF-alpha, IL-2 and interferon-gamma play an important role in acute GVHD. Attention has been recently focused on the role of TNF-alpha in acute GVHD. Serum TNF-alpha levels are elevated in human GVHD, blood and skin cells of patients with acute GVHD express TNF-alpha, antibodies to TNF-alpha ameliorate murine and human GVHD and infusion of TNF-alpha in mice induces changes that mimic GVHD. We hypothesize that engagement of la molecules on host cells by alloreactive donor T cells is an important inducer of TNF-alpha release in acute GVHD. Microbial superantigens which bind to la molecules may further contribute to TNF-alpha release from la+ monocytes, and from activated la+ T cells and keratinocytes present in acute GVHD. To define the mechanisms of induction of TNF-alpha gene expression via la molecules, we will: 1. Examine the induction of TNF-alpha in acute GVHD. We will: a) assess TNF-alpha expression in patients with acute GVHD, b) examine the induction of TNF-alpha in monocytes and T cells during alloreaction, c) examine the induction of TNF-alpha by superantigen. 2. Analyze the function and structure of la-coupled signal transducing pathways. We will: a) examine the activation of PKC by la ligands, b) examine the phospholipases and second messengers involved in PKC activation, c) examine the activation of tyrosine phosphorylation pathways by la ligands, d) identify la-associated molecules. 3. Identify the DNA response elements and regulatory proteins involved in transcriptional activation of TNF-alpha via la. We will examine: a) transcriptional activation of the TNF-alpha gene by la ligands using CAT assays and b) induction of specific nuclear protein/DNA complexes by la ligands. The studies proposed should provide a better understanding of the pathogenesis of acute GVHD and have important implications for la mediated signal transduction in immune cells as well as in non-immune cells which display aberrant la expression in inflammation cancer and autoimmunity.