HIV-1 infection of hematopoietic progenitor cells, their differentiation and seeding of virus into brain tissue

 描述（由申请人提供）：骨髓中的造血祖细胞（HPC）分化为髓样和淋巴样细胞谱系，分散到全身不同组织中。一些研究表明，HPCs可以在体外被HIV-1感染。我们的初步数据表明，嗜大嗜性R5变体（适用于使用低CD 4的巨噬细胞）感染脐带血HPC比非嗜大嗜性R5病毒更有效，通过细胞接触的感染是特别有效的。我们还表明，在体外感染的HPC存活分化和增殖成成熟的骨髓细胞。然后成熟细胞能够将病毒转移到易感靶细胞。我们的数据表明，单个HPC的感染有可能产生大量的HIV+成熟细胞。这样的成熟细胞将能够将艾滋病毒接种到全身不同的组织中。 据报道，骨髓中的HIV序列与脑中的HIV序列密切相关。这一结果与HIV+单核细胞（来源于感染的HPC）将HIV接种到大脑中一致，据报道发生在晚期疾病中。其他有限的研究尚未证实这一点。然而，骨髓含有许多细胞类型，包括成熟的巨噬细胞和淋巴样细胞，因此HIV的采样可能无法检测到来自HPC的病毒。在这里，我们将评估纯化的HPC中的HIV序列，并将其与脑中的HIV序列进行比较。 在这项提案中，我们的主要目标是研究（1）来自HIV+受试者骨髓的HPC是否携带HIV，以及它们是否可以分化为髓系或T细胞谱系细胞，然后将病毒转移到新细胞。以及（2）HPC中存在的HIV序列是否与脑组织中的HIV序列相关，以支持HIV从骨髓到脑的传播途径的存在。我们提出三个目标。目标1：确定HIV阴性成人骨髓HPC是否可以在体外感染，以及它们是否保留分化为髓系和T细胞谱系细胞的能力。我们将测试我们的数据显示HIV感染和脐带血HPC的分化是否适用于成人骨髓HPC目的2：确定来源于HIV+骨髓的HPC是否被感染并能分化为受感染的髓系和T细胞系细胞。我们将测试HIV阳性骨髓HPC向T细胞和髓系细胞的分化，并确定成熟细胞是否携带感染性和可转移的病毒。目的3：确定HPC中的HIV序列是否与脑组织中的HIV序列密切相关。我们将研究是否存在于HIV+骨髓HPC中的HIV序列与存在于患有HIV相关神经认知障碍（HAND）的相同HIV+患者脑中的病毒准种密切相关。 我们的假设是，HIV+ HPC分化为成熟的骨髓细胞和T细胞，将HIV分散到全身。如果得到支持，我们的研究结果将指出HPC在HIV发病机制和病毒储库形成中的重要作用，这在以前并没有得到重视。这一新的信息可能会导致新的战略，以确定艾滋病毒+HPC和衍生物，需要根除，如果艾滋病毒是在体内消除。

 DESCRIPTION (provided by applicant): Hematopoietic progenitor cells (HPCs) in bone marrow differentiate into both myeloid, and lymphoid cell lineages that disperse into different tissues throughout the body. Several studies indicate that HPCs can be infected by HIV-1 in vitro. Our preliminary data shows that mac-tropic R5 variants (adapted to use low CD4 on macrophages) infect umbilical cord blood HPCs more efficiently than non-mac-tropic R5 viruses and that infection via cell contact is particularly efficient. We also show that HPCs infected in vitro survive to differentiate and multiply into mature myeloid cells. Mature cells were then able to transfer virus to susceptible target cells. Our data indicates that infection of a single HPC would have the potential to produce large numbers of HIV+ mature cells. Such mature cells would be able to seed HIV into different tissues throughout the body. HIV sequences in bone marrow were reported to be closely related to those in brain. This result is consistent with HIV+ monocytes (derived from infected HPCs) seeding HIV into the brain, as reported to occur in late disease. Other limited studies have not confirmed this. However, bone marrow contains many cell types including mature macrophages and lymphoid cells, so that sampling of HIV may not detect virus from HPCs. Here, we will evaluate HIV sequences in purified HPCs and compare them with those in brain. In this proposal, our main goals are to investigate (1) whether HPCs from bone marrow of HIV+ subjects carry HIV and whether they can differentiate into myeloid or T-cell lineage cells that then transfer virus to new cells. And (2) whether HIV sequences present in HPCs are related to those in brain tissue, to support the presence of a bone marrow to brain dispersal route for HIV. We present three aims. Aim 1: Determine whether HIV-negative adult bone marrow HPCs can be infected in vitro and whether they retain the capacity to differentiate into myeloid and T-cell lineage cells. We will test if our data showing HIV infection and differentiation of umbilical cord blood HPCs applies to adult bone marrow HPCs Aim 2: Determine whether HPCs derived from HIV+ bone marrow are infected and can differentiate into infected myeloid and T-cell lineage cells. We will test differentiation of HIV+ bone marrow HPCs into both T- cell and myeloid lineage cells and establish whether mature cells carry infectious and transferable virus. Aim 3: Establish whether HIV sequences in HPCs are closely related to those in brain tissue. We will examine whether HIV sequences present in HIV+ bone marrow HPCs are closely related to viral quasispecies present in the brain of the same HIV+ patients with HIV-associated neurocognitive disorder (HAND). Our hypothesis is that HIV+ HPCs differentiate into mature myeloid and T-cells that disperse HIV through the body. If supported, our results will point to a major role for HPCs in HIV pathogenesis and formation viral reservoirs that has previously not been appreciated. This new information may lead to new strategies to identify HIV+ HPCs and derivatives that need to be eradicated if HIV is to be eliminated in vivo.