An immune-based approach for HIV eradication

基于免疫的艾滋病毒根除方法

• 批准号: 9031713
• 负责人: JUAN LAMA
• 金额: $ 122.64万
• 依托单位: RETROVIROX, INC.
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9031713
• 关键词: Adverse effects; Affect; Agonist; Antibodies; Appearance; Autologous; Award; Biochemical; Biological Assay; CD4 Lymphocyte Count; CD8B1 gene; Cells; Cessation of life; Chemicals; Chimeric Proteins; Chronic Disease; Data; Development; Down-Regulation; Family; Frequencies; Funding; Future; Genetic Transcription; Goals; HIV; HIV Infections; Health; Health system; Human; Immune; Immune response; Immune system; In Vitro; Infection; Interphase Cell; Interruption; Latent Virus; Lead; Life; Mediating; Metabolic; Modeling; Mus; Nucleic Acids; Oral; Patients; Permeability; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phase; Physiological; Preparation; Principal Investigator; Problem Solving; Process; Property; Protein Kinase C; Proteins; Rattus; Research; Resistance; Rodent Model; Role; Sampling; Series; Shock; Small Business Innovation Research Grant; Solubility; Source; Specificity; Surface; T-Cell Activation; Testing; Therapeutic Index; Validation; Viral; Viral Antigens; Viral Load result; Viral reservoir; Virus; Virus Diseases; Virus Replication; base; burden of illness; cell killing; cost; humanized mouse; improved; in vitro Model; in vitro testing; in vivo; in vivo Model; inhibitor/antagonist; killings; lead series; mouse model; novel; particle; pre-clinical; prevent; programs; purge; response; small molecule; small molecule inhibitor; social; social stigma; success; therapeutic vaccine

 DESCRIPTION (provided by applicant): Viral reservoir eradication has become a leading subject in the field of HIV research. A plethora of 26 antiretrovirals (ARVs) are available to efficiently treat infection. Living with HIV has become a chronic disease in which viral load can be controlled in over ninety percent of patients. Yet, the health, social, and economical burden of the disease are unprecedented. Social stigma, serious side effects accumulated during long-life treatments, and a tremendous cost to the health system, estimated at near half a million dollars throughout the life of a patient, highlight the need of a cure for HIV. Early in the courseof infection the virus becomes latent within resting cells and remains in a state in which no protein or nucleic acids are expressed, and no new viral particles are made. This reservoir of latentlyinfected cells is now seen as the primary barrier standing in the way of HIV eradication. Even in the presence of efficient cART, over 60 years are required to completely eliminate the reservoir, and alternative approaches to cure HIV are needed. Future efforts to eradicate HIV will likely be based on the so-called "shock and kill" approach, where the virus is first reactivatd from its latent reservoirs with "latency-reversing-agents" (LRAs), and a second therapy eliminates reactivated cells. Ex-vivo HIV reactivation assays with autologous virus have recently demonstrated the inability to eliminate reactivated cells in physiological settings. Several factor can explain the partial resistance to CTL-mediated killing, and also preventing death normally induced by the viral CPE. These factors include the low level of expression of viral antigens in reactivated cells and the intrinsic properties of HIV that allow the virus to escape the CTL immune response. In this Phase II program, we propose an HIV-specific immune-based approach to facilitate the killing of infected cells. In a previous Phase I award, we successfully identified small-molecule inhibitors of the Nefmediated MHC-I downmodulation. We characterized molecules that specifically block downmodulation of MHC-I in HIV infected cells without interfering with its surface levels in uninfected cells, and without affecting other unrelated host proteins. These inhibitors prevent the appearance of infected cells with low levels of sMHC-I, which cannot efficiently present viral antigens and are partially resistant to CTL killing. We propose to use these inhibitors to overcome the activity of Nef and facilitate the killng of latently infected cells after pharmacological reactivation with LRAs. The specific aims to optimize inhibitors through medicinal chemistry and identify a preclinical candidate are presented below: Specific Aim 1. Lead optimization of inhibitors of MHC-I downmodulation. Two lead series will be subjected to multiple iterative cycles of lead optimization to improve potency, specificity, metabolic stability, solubility, permeability and CYP profiles, with the goal to identfy a preclinical candidate. Specific Aim 2. Validation of advanced candidates with in vitro, ex-vivo and in vivo assays. Advanced molecules in one lead series will be used to test their effect after addition of CTLs to HIV replicating cells. Inhibitors will also be evaluated with and in-vivo model of HIV latency (humanized BLT mice) to determine whether they diminish the size of the viral reservoir and the frequency of viral rebound after LRA treatment. Specific Aim 3. Preliminary determination of m.o.a. Studies aimed at understanding the mechanism of action of these inhibitors will be carried out. Putative interactions with host partners will be interrogated and those that can be specifically blocked by the MHC-I inhibitors will be further investigated. Success in this Phase II application will be defined as the milestone identification of a preclinicl candidate with adequate PK properties in rats, predictive of oral use in humans. The preclinical candidate will have been validated in ex-vivo assays with samples of aviremic patients, and with the humanized BLT mouse model of latency. These studies may result in first-in-class inhibitors of a novel family of specific immune activators for use in HIV eradication approaches.

 描述(申请人提供)：根除病毒库已成为艾滋病毒研究领域的前沿课题。有过多的26种抗逆转录病毒药物(ARV)可用于有效治疗感染。艾滋病毒携带者已经成为一种慢性病，90%以上的患者的病毒载量可以控制。然而，这种疾病造成的健康、社会和经济负担是前所未有的。社会耻辱，在长期治疗期间积累的严重副作用，以及卫生系统的巨大成本--估计在患者的一生中接近50万美元--突显了治愈艾滋病毒的必要性。在感染过程的早期，病毒在静止细胞内潜伏，并保持在不表达蛋白质或核酸的状态，也不产生新的病毒颗粒。这种潜伏感染细胞的储备库现在被视为阻碍根除艾滋病毒的主要障碍。即使在有有效的CART存在的情况下，也需要60多年的时间才能完全消除这种蓄水池，还需要其他方法来治愈艾滋病毒。未来根除艾滋病毒的努力可能会基于所谓的“休克并杀死”方法，即首先用“潜伏期反转剂”(LRAs)从潜伏的蓄水池中重新激活病毒，然后第二种疗法消除重新激活的细胞。最近，用自体病毒进行的体外HIV重新激活试验表明，在生理环境中无法消除重新激活的细胞。几个因素可以解释对CTL介导的杀伤的部分抵抗，也可以防止通常由病毒CPE诱导的死亡。这些因素包括病毒抗原在重新激活的细胞中的低水平表达，以及艾滋病毒允许病毒逃避CTL免疫反应的固有特性。在这个第二阶段的计划中，我们提出了一种基于HIV特异性免疫的方法来促进对受感染细胞的杀灭。在之前的第一阶段奖中，我们成功地识别了Nef介导的MHC-I下调的小分子抑制剂。我们鉴定了一些分子，这些分子专门阻止艾滋病毒感染细胞中MHC-I的下调，而不干扰未感染细胞的表面水平，也不影响其他无关的宿主蛋白。这些抑制剂防止感染细胞出现低水平的sMHC-I，sMHC-I不能有效地呈递病毒抗原，并对CTL杀伤具有部分抵抗力。我们建议使用这些抑制剂来克服Nef的活性，并在LRAs药理重新激活后促进对潜伏感染细胞的杀伤。通过药物化学优化抑制剂并确定临床前候选药物的具体目标如下：具体目标1.引导MHC-I下调抑制剂的优化。两个导联系列将经历导联优化的多个迭代循环以提高效率， 特异性、代谢稳定性、溶解性、渗透性和CYP图谱，目的是确定临床前候选药物。具体目标2.用体外、体外和体内试验对高级候选进行验证。在将CTL添加到HIV复制细胞后，将使用一个铅系列中的先进分子来测试它们的效果。抑制剂也将通过体内模型进行评估。 对艾滋病毒潜伏期(人源化的BLT小鼠)进行研究，以确定它们在LRA治疗后是否减少了病毒库的大小和病毒反弹的频率。具体目标3.最大有效浓度的初步确定。将开展旨在了解这些抑制剂的作用机制的研究。将询问与宿主伙伴的假定相互作用，并将进一步调查那些可以被MHC-I抑制剂特别阻止的相互作用。这一第二阶段应用的成功将被定义为具有足够的大鼠PK特性的临床前候选药物的里程碑鉴定，预测在人类中的口服应用。临床前候选者将在体外无精症患者样本和人源化的BLT潜伏期小鼠模型中得到验证。这些研究可能导致一类新的特定免疫激活剂家族的一流抑制剂，用于根除艾滋病毒的方法。