INFECTIVITY OF HSIV-VIF CHIMERA IN NEWBORN PIGTAILED MACAQUES

HSIV-VIF 嵌合体在新生短尾猴中的感染性

基本信息

批准号：
8357619
负责人：
Shiu-Lok Hu
金额：
$ 37.79万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-05-01 至 2012-04-30
项目状态：
已结题

项目摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Currently, there is no animal model for HIV-1 infection and disease because the virus is highly specific for humans. Macaques are generally resistant to HIV-1, with the exception being pig-tailed macaques. Our lab showed that pig-tailed macaques are unable to express functional isoforms of TRIM5-alpha, which has been identified as a host factor that restricts the replication of HIV-1 in rhesus monkeys. Therefore, it is possible that HIV-1 will only need to overcome restriction by another host factor, APOBEC3G/F, to replicate successfully in pig-tailed macaques. To test this hypothesis, we collaborated with Dr. J. Kimata of Baylor College of Medicine, who engineered an HIV-1 clone that includes the vif gene of SIVmne, allowing it to counteract APOBEC3G/F-mediated restriction. This chimeric virus, HSIV-vif, is 96% HIV-1 and 4% SIV. It replicates in stimulated pig-tailed macaque blood cells as efficiently as SIVmne. In another pilot study, we inoculated 2 juvenile pig-tailed macaques intravenously with HSIV-vif. Although both animals became infected, plasma viremia did not sustain beyond 10 months after infection. Since newborn animals are more susceptible to lentiviral infection and disease, we inoculated two newborn pig-tail macaques with HSIV-vif. Both animals were infected, with a peak plasma viral load of 0.5-1x105 copies/ml. Although viral load decreased to baseline (100 copies/ml) after acute phase infection, it rebounded in both animals between week 28 and 44, indicating persistent infection. Comparative studies allowed us to identified two notable differences between the Pt-tropic HIV-1 and SIVmne (1) SIV Vif does not associate with Pt-tropic HIV-1 viral particles; (2) while Pt-tropic HIV-1 degrades both Pt APOBEC3G and APOBEC3F, it prevents their inclusion in virions to a lesser extent than pathogenic SIVmne. Thus, while SIV Vif is necessary for persistent infection by Pt-tropic HIV-1, improved expression and inhibition of APOBEC3 proteins may be required for robust viral replication in vivo.

该子项目是利用资源的众多研究子项目之一由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持并且子项目的主要研究者可能是由其他来源提供的，包括其他 NIH 来源。子项目可能列出的总成本代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。目前，还没有 HIV-1 感染和疾病的动物模型，因为该病毒对人类具有高度特异性。猕猴普遍对 HIV-1 具有抵抗力，但猪尾猕猴除外。我们的实验室表明，猪尾猕猴无法表达 TRIM5-alpha 的功能亚型，TRIM5-alpha 已被确定为限制 HIV-1 在恒河猴中复制的宿主因子。因此，HIV-1可能只需要克服另一个宿主因子APOBEC3G/F的限制，就能在猪尾猕猴中成功复制。为了检验这一假设，我们与贝勒医学院的 J. Kimata 博士合作，他设计了一个 HIV-1 克隆，其中包含 SIVmne 的 vif 基因，使其能够抵消 APOBEC3G/F 介导的限制。这种嵌合病毒 HSIV-vif 的成分为 96% HIV-1 和 4% SIV。它在受刺激的猪尾猕猴血细胞中复制的效率与 SIVmne 一样。在另一项试点研究中，我们给 2 只幼年猪尾猕猴静脉注射了 HSIV-vif。尽管两只动物均被感染，但血浆病毒血症在感染后并未持续超过 10 个月。由于新生动物更容易受到慢病毒感染和疾病，我们给两只新生猪尾猕猴接种了 HSIV-vif。两只动物均被感染，血浆病毒载量峰值为 0.5-1x105 拷贝/毫升。尽管急性期感染后病毒载量下降至基线（100 拷贝/毫升），但两只动物的病毒载量在第 28 周至第 44 周期间均出现反弹，表明持续感染。比较研究使我们能够确定 Pt 向性 HIV-1 和 SIVmne 之间的两个显着差异 (1) SIV Vif 与 Pt 向性 HIV-1 病毒颗粒无关； (2) 虽然 Pt-tropic HIV-1 会降解 Pt APOBEC3G 和 APOBEC3F，但它阻止它们包含在病毒体中的程度比致病性 SIVmne 的程度要小。因此，虽然 SIV Vif 对于 Pt-tropic HIV-1 的持续感染是必需的，但 APOBEC3 蛋白的表达和抑制的改善可能是病毒在体内复制的必需因素。