Activity of novel drug candidates in primary cell models of HIV latency

潜伏感染、静止的CD4T细胞是根除HIV-1的中心障碍。主要障碍是外周血中潜伏感染细胞的频率较低，以及缺乏可将它们与未感染细胞区分开来的已知表型标记。这些障碍促使了潜伏期体外细胞模型的发展。这样的模型允许操纵细胞和病毒特征，以获得对潜伏期是如何建立和调节的机械理解。然而，没有一个单一的艾滋病毒潜伏期实验系统被认为完全概括了体内潜伏病毒库的生物学特性。这主要是因为：(A)艾滋病毒建立潜伏期的机制是多方面的；(B)潜伏感染的细胞类型也是多种多样的。关于特定刺激(如激活/分化、稳态增殖、细胞因子)和病毒因素(如整合位点、TAT驱动表达)如何影响实验系统中潜在储存库的动态，已获得了丰富的知识。项目2.2将对新的小分子化合物和化合物的组合进行“二级”表征，这些化合物已被哈祖达博士的小组在项目2.1中通过初步筛选确定为可诱导艾滋病毒转录。在目标1和目标2中，我们建议使用一组特征良好的原代细胞系统和一个Jurkat细胞系克隆来验证候选药物化合物。第三个目标是开发更多的原代细胞模型，以便能够研究艾滋病毒在其他相关细胞类型中的潜伏期，这些细胞类型以前没有在体外探索过(例如，过渡性记忆T细胞和巨噬细胞)。在至少一个初级培养系统中有效的治疗，如果没有表现出明显的毒性或诱导细胞激活/增殖，将被转移到Delaney协作计划内的后续表征和开发阶段。这将包括详细的机制研究(目标1)，在人源化的小鼠和非人类灵长类动物中的活动测试(目标3)和在患者细胞体外的活动(目标4)。我们的最终目标是找到新的药物和药物组合，当应用于患者的治疗策略时，这些药物和药物组合将具有很高的成功激活艾滋病毒潜伏病毒的可能性。

Latently infected, quiescent CD4 T cells represent a central obstacle to eradication of HIV-1. Major hurdles are the low frequencies of latently infected cells in peripheral blood and the lack of known phenotypic markers that can distinguish them from uninfected ones. These impediments have prompted the development of in vitro cell models of latency. Such models allow manipulation of cellular and viral characteristics to gain a mechanistic understanding of how latency is established and regulated. However, no single experimental system of HIV latency is perceived to completely recapitulate the biology of the latent viral reservoir in vivo. This is mainly because (a) the mechanisms for establishment of latency by HIV are multiple; and (b) the types of cells harboring latent infection are also multiple. A wealth of knowledge has been gained regarding how specific stimuli (e.g. activation/differentiation, homeostatic proliferation, cytokines) and viral factors (e.g. integration site, Tat-driven expression) influence the dynamics of latent reservoirs in experimental systems. Project 2.2 will perform "secondary level" characterization of novel small molecule compounds and combinations of compounds that have been identified to induce HIV transcription through primary screening by Dr. Hazuda's group in Project 2.1. In Aims 1 and 2, we propose to use a panel of well-characterized primary cell systems and one Jurkat-based cell line clone to validate candidate drug compounds. A third Aim will be the development of additional primary cell models to enable the study of HIV latency in other relevant cell types, not previously explored ex vivo (e.g. transitional memory T cells and macrophages). Treatments that are active in at least one of the primary culture systems, without showing overt toxicity or induction of cellular activation/proliferation, will be moved to subsequent phases of characterization and development within the Delaney Collaborative program. This will include detailed mechanistic studies (Objective 1), testing for activity in humanized mice and non-human primates (Objective 3) and in patient cells ex vivo (Objective 4). Our ultimate goal is to identify novel drugs and drug combinations that will have a high probability for success in activating HIV latent viruses when applied to treatment strategies in patients.