CYCLOSPORINE AND GENE EXPRESSION BY HUMAN THYMOCYTES

环孢菌素和人类胸腺细胞的基因表达

• 批准号: 3140228
• 负责人: GABRIELLE H REEM
• 金额: $ 14.01万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3140228
• 关键词: DNA binding protein; DNA footprinting; T lymphocyte; blood /lymphatic pharmacology; calcium metabolism; cell population study; chlorpromazine; cyclosporines; drug metabolism; drug receptors; drug resistance; flow cytometry; gene expression; genetic transduction; human tissue; immunofluorescence technique; interleukin 2; leukocyte activation /transformation; lymphokines; monoclonal antibody; nucleic acid hybridization; nucleic acid probes; nucleic acid sequence; nucleoproteins; phosphatidylinositols; phosphoproteins; phosphorylation; protein kinase C; radioimmunoassay; regulatory gene; thymus; tissue /cell culture; transcription factor

The objective of this proposal is the elucidation of the mechanism of action of cyclosporine (CsA). Cyclosporine acts by inhibiting the activation of tissue specific genes which can be induced in vitro by activating thymocytes and T-cells with agents which initiate a partially known cascade of transducing signals. The mechanism of action of a drug such as cyclosporine which specifically inhibits the expression of genes which are coordinately expressed during the activation of thymocytes or T- cells can be analysed by using approaches aimed at identifying and characterizing cis-acting DNA sequences (recognition elements) required for eukaryotic gene regulation. The known transcription factors of several inducible tissue-specific genes are preexisting and are modified during activation by a posttranscriptional mechanism which does not require protein synthesis; whereas others require newly synthesized proteins to induce their expression. Positive and negative regulatory elements which function in response to extracellular agents have been identified. It is my working hypothesis, that CsA can inhibit the induction of genes coding for lymphokines either directly, by binding to DNA in concert with a regulatory protein, or indirectly by affecting the modification of one or more putative, regulatory proteins (this modification can be either covalent or allosteric), or by influencing the binding of regulatory proteins to "CsA regulatory sequences" on the gene. My goal is to identify subsets of thymocytes resistant to the effects of CsA since it has been proposed that a specific subset of T-cells is relatively resistant to CsA. The comparison of the effects of CsA on uninduced and induced thymocytes will be useful for the understanding of the molecular events which are elicited during induction and inhibited by CsA. The effect of CsA on the cascade of transducing signals elicited by extracellular inducers and its effect on Ca+2 will also be studied.

这项建议的目的是阐明这种机制。 环孢素(CsA)的作用。环孢素通过抑制 可被诱导的组织特异性基因的激活 在体外通过使用以下试剂激活胸腺细胞和T细胞 启动部分已知的传感信号级联。这个 一种药物的作用机制，如环孢素 特异地抑制基因的表达 在胸腺细胞或T-细胞激活过程中协同表达 可以通过使用旨在识别和识别细胞的方法来分析细胞 表征顺式作用的DNA序列(识别元件) 真核基因调控所必需的。已知的抄本 几个可诱导的组织特异性基因的因子是预先存在的 并在激活过程中通过转录后修饰 不需要蛋白质合成的机制；而 其他人则需要新合成的蛋白质来诱导他们的 表情。积极和消极的监管要素 对胞外因子的反应功能已被确定。 这是我的工作假说，CsA可以抑制诱导 通过与DNA结合直接编码淋巴因子的基因 与调节蛋白协同作用，或通过影响 修饰一个或多个推定的、调节蛋白(这 修饰可以是共价的或变构的)，或者通过 影响调控蛋白与CsA调控蛋白的结合 我的目标是识别出基因的亚群 胸腺细胞对环孢素A的影响具有抵抗力 提出了一种特定的T细胞亚群对 CsA。环孢素A对非诱导性和非诱导性血管紧张素转换酶的影响比较 诱导的胸腺细胞将有助于理解 诱导和抑制过程中诱发和抑制的分子事件 由CSA提供。CSA对换能信号级联的影响 胞外诱导剂的诱导及其对钙离子的影响 被研究。