Prime shock and kill for HIV erradication

为根除艾滋病毒提供休克和杀戮

• 批准号: 9889021
• 负责人: ANDREW D BADLEY
• 金额: $ 75.29万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9889021
• 关键词: AIDS prevention; Anti-Retroviral Agents; Apoptosis; Apoptotic; Archives; BCL-2 Protein; BLT mice; Binding; Bortezomib; CD4 Positive T Lymphocytes; Cause of Death; Cell Death; Cell physiology; Cells; Cessation of life; Characteristics; Chronic; Cleaved cell; Clinic; Clinical; Clinical Trials; Complex; Cytosol; Data; Diagnosis; Disease; Disease Management; Drug resistance; Ebola virus; Environment; FDA approved; Frequencies; Funding; Genetic Polymorphism; Genetic Transcription; Genotype; Goals; Grant; HIV; HIV Infections; HIV Protease; HIV resistance; HIV therapy; Helper-Inducer T-Lymphocyte; Heterogeneity; Human; Immune; Immune response; Immunologic Deficiency Syndromes; Induction of Apoptosis; Infection; Infectious Agent; Ionizing radiation; Laboratories; Ligation; Lymphoid; Lymphoid Tissue; Measures; Modeling; Obstruction; Pathway interactions; Patients; Pharmacology; Phenotype; Prevalence; Prevention; Proteasome Inhibitor; Proteins; Publishing; Puma; Regulation; Resistance; Respondent; Shock; Signal Transduction; Stimulus; Symptoms; T memory cell; T-Lymphocyte; TP53 gene; Testing; Time; Toxic effect; Up-Regulation; Vaccines; Viral; Viral Proteins; Virus; antiretroviral therapy; bak protein; base; cell killing; cell type; clinically relevant; in vivo; inhibitor/antagonist; insight; memory CD4 T lymphocyte; multicatalytic endopeptidase complex; novel; peripheral blood; pro-apoptotic protein; resistance mechanism; response; success; transmission process; treatment optimization

PROJECT SUMMARY When people encounter an infectious agent or a vaccine for the first time, they develop an immune response to that agent or vaccine. Some of the respondent cells may persist for years – even decades, becoming memory T cells, so that if the infectious agent is again encountered, the subsequent immune response can be rapid and exact. Since these cells must to persist for long periods, they have developed mechanisms to resist the normal process of cell turnover, i.e., these cells withstand death signals. HIV infection is a chronic, manageable disease that, as yet, cannot be cured due to the persistence of HIV in memory CD4 T cells that are resistant to cell turnover and death. In T cells that are not memory CD4 T cells, replicating HIV produces HIV proteins, which are toxic and kill the T cell. Paradoxically, when HIV is reactivated in memory CD4 T cells, these same HIV proteins do not kill the cell. We believe the reason these memory CD4 T cells do not die after HIV is reactivated, is that they are intrinsically resistant to cell death. Accordingly there are multiple levels of regulation within cells that together determine whether a cell will, or will not undergo cell death. In broad terms in order for a cell to undergo apoptosis (one form of cell death) two conditions must be met: (i) a pro-apoptotic stimulus, and (ii) a permissive cellular environment, where anti-apoptotic machinery does not prevent propagation of the pro-apoptotic signal. Our laboratory group has studied how HIV causes the death of CD4 T cells, focusing on the HIV protease- Casp8p41 pathway. During the course of this grant's last funding cycle, we discovered that Casp8p41 kills cells by binding to the pro-apoptotic protein Bak. Conversely, if Casp8p41 binds the anti-apoptotic protein Bcl2, then HIV does not kill a cell, instead becoming a persistent, latently-infected reservoir cell. We have generated novel and clinically relevant observations that antagonizing Bcl2 with a Bcl2 inhibitor (venetoclax) alters the number of infected cells that die following HIV reactivation, reducing the HIV reservoir size. Similarly, we have shown that after Casp8p41 is bound by Bcl2, the complex is polyubiquitinated and degraded by the proteasome. Consequently, using clinically available proteasome inhibitors (bortezomib or ixazomib) causes accumulation of Casp8p41, enhances infected cell killing, alters the number of dead infected cells following HIV reactivation, and effectively reduces the HIV reservoir size. The focus of the current application is to optimize these treatment approaches to: (i) test combinations of Bcl2 antagonists with optimized latency- reversal strategies, (ii) test the effect of the most promising combinations on the lymphoid HIV reservoir, and (iii) determine why some, but not all, patients cells respond to Bcl2 inhibition, testing the hypothesis that polymorphisms, or differences in expression of key proteins involved in this pathway, differ between responders and nonresponders.

项目摘要 当人们第一次接触传染源或疫苗时，他们会产生免疫反应， 这种药物或疫苗。一些反应细胞可能会持续数年甚至数十年，成为记忆。 T细胞，这样，如果再次遇到感染因子，随后的免疫反应可以是快速的， 确切由于这些细胞必须长期存在，它们已经发展出抵抗正常细胞的机制。 细胞周转的过程，即，这些细胞能承受死亡信号艾滋病毒感染是一种慢性、可控制的 这种疾病，到目前为止，由于艾滋病毒在记忆CD 4 T细胞中的持续存在而无法治愈， 细胞更新和死亡。在不是记忆性CD 4 T细胞的T细胞中，复制HIV产生HIV蛋白， 它们是有毒的，会杀死T细胞。奇怪的是，当HIV在记忆性CD 4 T细胞中被重新激活时，这些相同的 HIV蛋白质不会杀死细胞。我们认为这些记忆性CD 4 T细胞在感染艾滋病毒后不死亡的原因是， 重新激活，是它们本质上抵抗细胞死亡。因此，有多个层次的 细胞内的调节共同决定细胞是否会经历细胞死亡。从广义上讲 为了使细胞经历细胞凋亡（细胞死亡的一种形式），必须满足两个条件：（i）促细胞凋亡 刺激，和（ii）允许的细胞环境，其中抗凋亡机制不阻止 促凋亡信号的传播。 我们的实验室小组研究了艾滋病毒如何导致CD 4 T细胞死亡，重点是艾滋病毒蛋白酶- Casp 8 p41通路。在这项资助的最后一个资助周期中，我们发现Casp 8 p41可以杀死 通过与促凋亡蛋白巴克结合来抑制细胞凋亡。相反，如果Casp 8 p41结合抗凋亡蛋白Bcl 2， 那么HIV不会杀死细胞，而是成为一个持久的、潜在感染的储存细胞。我们已经生成 新的和临床相关的观察，拮抗Bcl 2与Bcl 2抑制剂（维奈托克）改变了 HIV重新激活后死亡的感染细胞数量，减少HIV储存库的大小。同样地，我们有 结果表明，在Casp 8 p41与Bcl 2结合后，复合物被多聚泛素化并被 蛋白酶体因此，使用临床可用的蛋白酶体抑制剂（硼替佐米或ixazomib）会导致 Casp 8 p41的积累增强了感染细胞的杀伤，改变了感染后死亡细胞的数量。 重新激活艾滋病病毒，并有效地减少艾滋病病毒库的大小。当前应用程序的重点是 优化这些治疗方法以：（i）测试具有优化的潜伏期的Bcl 2拮抗剂的组合， 逆转策略，（ii）测试最有希望的组合对淋巴HIV储库的影响，和 (iii)确定为什么一些，但不是全部，患者细胞响应Bcl 2抑制，测试假设， 多态性，或参与该途径的关键蛋白质表达的差异， 应答者和无应答者。