Procaspase 8 Activation by HIV Protease

HIV 蛋白酶激活半胱氨酸蛋白酶原 8

• 批准号: 6888175
• 负责人: ANDREW D BADLEY
• 金额: $ 33.19万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6888175
• 关键词: HIV infections; SCID mouse; apoptosis; aspartic endopeptidases; clone cells; cysteine endopeptidases; cytotoxicity; enzyme activity; enzyme mechanism; helper T lymphocyte; human data; human immunodeficiency virus; nucleic acid sequence; protein protein interaction; tissue /cell culture; virus cytopathogenic effect; virus genetics; virus protein

DESCRIPTION (provided by applicant): It remains controversial as to how CD4+ T cells directly infected with HIV die following infection. Numerous mechanisms have been proposed to account for infected cell killing, however none of the proposed mechanisms are universally accepted. It has long been recognized that one HIV protein, HIV protease, is intrinsically cytotoxic as its expression causes the death of bacteria, yeast, and mammalian cells, however it remains unclear how HIV protease kills these cells. Experimental data now demonstrate that HIV protease cleaves host cell proteins in addition to viral proteins. Our laboratory has recently defined one mechanism by which HIV protease can kill cells; specifically HIV protease can cleave the apoptosis initiating protein, procaspase 8, to result in its activation. Thereafter, a traditional apoptosis cascade is initiated, ultimately resulting in the structural, nuclear, and morphologic changes associated with apoptosis. While we have demonstrated that this mechanism of HIV protease mediated killing can occur, we have yet to determine whether or not this mechanism does occur, particularly in vivo. The focus of the current proposal is to define the relevance of this form of cell killing both in infections, which occur in the test tube, as well as in patients. The clinical significance of this research may be reflected in recent clinical observations, suggesting an altered diseased course of patients who have infections with HIV that contain mutations within the HIV protease gene as compared to those that do not. We will explore the potential impact of these mutations by assessing the differential impact of wild type HIV protease versus mutant protease on procaspase 8 activation and cell killing.

描述（申请人提供）：直接感染HIV的CD4+T细胞在感染后如何死亡仍存在争议。已经提出了许多机制来解释感染细胞的杀伤，但是所提出的机制没有一个被普遍接受。人们早已认识到，一种HIV蛋白——HIV蛋白酶——具有内在的细胞毒性，因为它的表达会导致细菌、酵母和哺乳动物细胞死亡，但目前还不清楚HIV蛋白酶如何杀死这些细胞。现在的实验数据表明，HIV 蛋白酶除了切割病毒蛋白外，还能切割宿主细胞蛋白。我们的实验室最近定义了一种 HIV 蛋白酶杀死细胞的机制；具体而言，HIV 蛋白酶可以裂解凋亡启动蛋白 procaspase 8，从而导致其激活。此后，传统的细胞凋亡级联启动，最终导致与细胞凋亡相关的结构、细胞核和形态学变化。虽然我们已经证明这种 HIV 蛋白酶介导的杀伤机制可以发生，但我们尚未确定这种机制是否确实发生，特别是在体内。当前提案的重点是确定这种形式的细胞杀伤在试管中发生的感染以及患者中的相关性。这项研究的临床意义可能反映在最近的临床观察中，表明与那些没有感染 HIV 蛋白酶基因的患者相比，感染 HIV 且含有 HIV 蛋白酶基因突变的患者的病程发生了改变。我们将通过评估野生型 HIV 蛋白酶与突变型蛋白酶对 procaspase 8 激活和细胞杀伤的差异影响来探索这些突变的潜在影响。