HIV-1 Persistence in the CNS and Myeloid Cells

描述(申请人提供)：很明显，HIV-1可以在中枢神经系统建立一个独立的复制种群，这也可以导致嗜巨噬细胞HIV-1的进化，其定义是进入低水平CD4的细胞的能力。然而，感染细胞在脑内的分布和巨噬细胞嗜性病毒在中枢神经系统外的发生都是有争议的，这两点都是确定根除HIV-1战略的重要考虑因素。随着最近广泛认识到聚合酶链式反应介导的重组可以扰乱系统发育信息，以及在聚合酶链式反应(单基因组扩增)中使用模板终点稀释对于准确定义病毒种群是必不可少的，我们对病毒种群的理解有了显著的提高。同样，进化过程建模程序的改进使系统发育关系的评估更加稳健，例如纳入了贝叶斯分析程序Beast。最后，与使用高度可变的单核细胞来源的巨噬细胞制剂试图对进化到使用低水平的CD4进入细胞的病毒进行表型相比，对细胞进入的CD4依赖性的定量描述提供了一个更可靠的巨噬细胞趋向性的定义。我们正在应用所有这三项重要进展来了解嗜巨噬细胞病毒的进化及其在发病机制中的作用，并了解它们创建长期宿主的潜力。我们最近将这些工具结合在一起来研究病毒的区隔，包括通过检查脑脊液中的病毒来研究中枢神经系统的区隔。我们现在已经将这些研究扩展到包括国家神经艾滋病组织联盟(NNTC)的样本。我们建议利用这些样本的可用性，在尸检前和尸检时，绘制出病毒在大脑中复制的位置，在如何感染病毒的受试者和那些接受治疗的受试者中。我们还将确定巨噬细胞嗜性病毒在大脑复制中心中的作用，以及这种类型的进化变体在中枢神经系统之外建立的能力。最后，我们将检查停止治疗后出现的早期反弹病毒的表型，因为这是根除策略必须面对的第一种病毒。

DESCRIPTION (provided by applicant): It is clear that HIV-1 can establish an independently replicating population in the CNS, and that this can also lead to the evolution of macrophage-tropic HIV-1, defined as the ability to enter cells with low levels of CD4. However, the distributin of infected cells in the brain and the occurrence of macrophage-tropic virus outside of the CNS are both controversial and both of these points are important considerations in defining strategies for the eradication of HIV-1. Our understanding of viral populations has been significantly improved with the recent widespread acknowledgement that PCR-mediated recombination can scramble phylogenetic information, and that the use of template end-point dilution in PCR (single genome amplification) is essential to define viral populations accurately. Similarly, improvements in programs modeling evolutionary processes make the assessment of phylogenetic relationships more robust, for example incorporating the Bayesian analysis program BEAST. Finally, quantitative descriptions of CD4 dependence for cell entry provide a much more robust definition of macrophage tropism than using highly variable monocyte-derived macrophage preparations to try to phenotype viruses that have evolved to use low levels of CD4 to enter cells. We are applying all three of these important advances to understand the evolution of macrophage-tropic viruses and their role in pathogenesis and to understand their potential to create a long-lived reservoir. We have recently brought these tools together to study viral compartmentalization, including compartmentalization in the CNS by examining virus in the CSF. We have now extended these studies to include samples from the National NeuroAIDS Tissue Consortium (NNTC). We propose to exploit the availability of these samples, taken both prior to and at autopsy, to map the sites of viral replication in the brain in subjects how are viremic and those on therapy. We will also define the role of macrophage-tropic virus in populating centers of replication in the brain, and the ability of this type of evolutionary variant to become established outside of the CNS. Finally, we will examine the phenotype of the early rebound virus that appears after therapy discontinuation, as this represents the first virus that eradication strategies must confront.