IMMUNOSUPPRESSION IN CANCER PATIENTS

癌症患者的免疫抑制

基本信息

批准号：
3166604
负责人：
ARTHUR DALE BANKHURST
金额：
$ 15.88万
依托单位：
UNIVERSITY OF NEW MEXICO
依托单位国家：
美国
项目类别：
财政年份：
1989
资助国家：
美国
起止时间：
1989-01-06 至 1991-12-31
项目状态：
已结题

项目摘要

Natural killer (NK) cells are large granular lymphocytes that spontaneously lyse a limited range of target and may be important in the protection of the host against the development of cancer and certain infectious diseases. In this proposal we will examine how mevalonate (MVA) and its metabolites regulate human NK cytotoxicity and locomotion. MVA is the product of 3-hydroxy-3-methyglutaryl Coenzyme A (HMG CoA) reductase, the major regulatory enzyme of cholesterol and other biosynthetic pathways. We have shown in preliminary experiments that specific inhibition of HMG CoA reductase with inhibitors such as lovastatin impairs NK cell cytotoxicity and locomotion. This inhibition is rapidly reversed by the addition of MVA which indicates that a MVA metabolite is required for these NK cell functions. In addition, we have shown that interleukin-2 (IL-2) can reverse the impairment of cell function associated with reductase inhibition. The kinetics of reversal with IL-2 are much slower than that seen with MVA. The particular focus of this proposal is to examine how MVA and its metabolites regulate NK function. The specific aims of the proposal are as follows: First, the precise step in NK cytotoxicity which is impaired by inhibition of HMG CoA reductase will be identified. Our preliminary data indicates that step 1 (conjugation) is inhibited as well as a post conjugation step. These studies on step 1 will involve examinations of membrane fluidity and the NK recognition structure using monoclonal antibody and flow cytometry techniques. The post conjugation events will be studied from the viewpoint of intracellular Ca++ changes, cytoskeletal changes, and protein phosphorylation involved in degranulation. Second, the metabolic fate of radiolabelled MVA during short term rescue of HMG CoA reductase inhibition will be examined. This will involve an analysis of the incorporation of (3H)MVA into cellular components. Third, the mechanism by which IL-2 reverses HMG CoA inhibition will be identified. These studies will examine if IL-2 directly modulates either HMG CoA reductase or the pre-reduction enzymes such as HMG CoA synthase. Fourth, the mechanism by which NK cell locomotion is impaired following HMG CoA reductase inhibition will be studied. This will involve studies on whether HMG CoA inhibition interferes with chemoattractant receptor expression, the initial acquisition of locomotor capacity by NK cells, or cytoskeletal events involved in NK cell movement. The use of specific inhibition of HMG CoA reductase will enable us to address major, unanswered questions regarding several aspects of human NK cell regulation.

天然杀手（NK）细胞是大的颗粒状淋巴细胞自发裂解有限的目标范围，可能很重要保护宿主免受癌症的发展和某些传染病。在此提案中，我们将研究如何 Mevalonate（MVA）及其代谢产物调节人NK细胞毒性和运动。 MVA是3-羟基-3-甲基戊二酰的产物辅酶A（HMG COA）还原酶，这是主要调节酶胆固醇和其他生物合成途径。我们显示了特定抑制HMG COA的初步实验与抑制剂（如lovastatin）还原型损害NK细胞的还原酶细胞毒性和运动。这种抑制迅速逆转通过添加MVA，表明MVA代谢物为这些NK细胞函数所需。此外，我们已经显示白介素2（IL-2）可以逆转细胞的损害与还原酶抑制相关的功能。动力学 IL-2的逆转比MVA所看到的要慢得多。这该建议的特别重点是检查MVA及其如何代谢物调节NK功能。特定目标建议如下：首先，NK的确切步骤抑制HMG COA还原酶受损的细胞毒性将被确定。我们的初步数据表明步骤1 （结合）被抑制以及结合后步骤。这些对第1步的研究将涉及检查膜使用单克隆抗体的流动性和NK识别结构和流式细胞仪技术。帖子结合活动将从细胞内CA ++的角度研究，研究细胞骨架变化和参与的蛋白质磷酸化脱粒。其次，放射性标记的MVA的代谢命运在短期营救HMG COA还原酶抑制期间检查。这将涉及对掺入的分析（3H）MVA进入细胞成分。第三，其机制 IL-2逆转HMG COA抑制作用。这些研究将检查IL-2是否直接调节任何一个HMG COA还原酶或还原前的酶，例如HMG COA合酶。第四， HMG COA后，NK细胞运动受到损害的机制还将研究还原酶抑制。这将涉及研究关于HMG COA抑制是否会干扰趋化剂受体表达，运动能力的最初采集由NK细胞或NK细胞运动涉及的细胞骨架事件。使用特定抑制HMG COA还原酶将使我们解决专业的，关于几个方面的未解决的问题人类NK细胞调节的。