Toward a new world monkey model of HIV-1 infection

性状（由申请方提供）：逆转录病毒在其天然宿主种属以外的种属中的复制可在病毒生命周期的多个步骤中被阻断。近年来，在描述这些限制的机制方面取得了重大进展。在本提案中，我们寻求利用并扩展这些观察结果，以产生在猫头鹰猴PBMC（omPBMC）中有效复制的HIV-1，这是开发HIV-1感染新动物模型的第一步。目前还没有HIV-1感染的动物模型。这样的模型将是有用的，在评估HIV-1的治疗，疫苗研究，并在研究HIV-1的发病机制。在初步的数据，我们表明，两个新的世界猴，猫头鹰猴（Aotus trivirgatus）和普通的绒猴（Callithrixjacchus），但不是那些松鼠猴（Saimiri sciureus）的进入限制，可以很容易地克服。我们还观察到，绒猴表现出没有后进入障碍，而且，如前所述，进入后障碍猫头鹰猴可以通过在病毒gag基因的点突变来克服。我们表明，猫头鹰猴细胞系，OMK，稳定表达猫头鹰猴CD 4和CXCR 4允许强大的病毒复制，表明没有额外的限制存在于这些细胞。然而，组装在猫头鹰猴PBMC中的HIV-1病毒粒子在其随后感染表达受体的OMK细胞的能力方面大大减弱，并且这些PBMC表达比OMK细胞显著更高水平的APOBEC 3G。我们发现，NL 4 -3 vif部分下调猫头鹰猴APOBEC 3G，但不能下调绒猴APOBEC 3G。这些数据表明，APOBEC 3蛋白是猫头鹰猴PBMC中HIV-1复制的关键但可克服的障碍。因此，本提案的重点是理解和克服猫头鹰猴细胞中部分APOBECS介导的限制，并进一步使HIV-1适应猫头鹰猴PBMC中的有效复制。适应病毒将进一步修改它们的env和nef基因，以增强病毒在面对猫头鹰猴免疫反应时的复制。改良病毒将进一步传代，并用于连续挑战新英格兰灵长类动物研究中心的猫头鹰猴，这项工作将在那里进行。

DESCRIPTION (provided by applicant): Replication of retroviruses in species other than their natural host species can be blocked at multiple steps in the viral lifecycle. In recent years, significant progress has been made in describing mechanisms underlying these restrictions. In this proposal we seek to use and extend these observations to generate an HIV-1 that efficiently replicates in owl monkey PBMC (omPBMC), a first step toward developing a new animal model of HIV-1 infection. No animal model of HIV-1 infection currently exists. Such a model would be useful in the evaluation of HIV-1 therapuetics, in vaccine studies, and in studies of HIV-1 pathogenesis. In preliminary data we show that the entry restrictions of two new world monkeys, the owl monkey (Aotus trivirgatus) and the common marmoset (Callithrixjacchus), but not those of the squirrel monkey (Saimiri sciureus), can be readily overcome. We also observe that marmosets exhibit no post-entry barrier, and that, as has been previously demonstrated, the post-entry barrier in owl monkeys can be overcome through a point mutation in the viral gag gene. We show that the owl monkey cell line, OMK, stably expressing owl monkey CD4 and CXCR4 permits robust viral replication, indicating that no additional restrictions are present in these cells. However, HIV-1 virions assembled in owl monkey PBMC are greatly attenuated in their ability to subsequently infect receptor-expressing OMK cells, and these PBMC express substantially higher levels of APOBEC3G than OMK cells. We show that NL4-3 vif partially down-regulates owl monkey APOBEC3G but is unable to down-regulate marmoset APOBEC3G. These data suggest that APOBEC3 proteins are a critical but surmountable impediment to replication of HIV-1 in owl monkey PBMC. Accordingly, the focus of this proposal is to understand and overcome the partial APOBECS-mediated restriction in owl-monkey cells, and to further adapt HIV-1 for efficient replication in owl-monkey PBMC. Adapted viruses will be further modified in their env and nef genes to enhance viral replication in the face of the owl monkey immune response. Modified virus will be further passaged and used to serially challenge owl monkeys housed at the New England Primate Research Center, where this work will be performed.