Pigtail Macaque Model of Human-Simian Immunodeficiency Virus Infection

摘要/摘要： 常用的HIV-1动物模型包括猕猴感染猿猴免疫缺陷病毒 (SIV)或猿猴-人类免疫缺陷病毒(SIV)，含有HIV包膜(Env)或逆转录酶。 这些动物模型在了解艾滋病毒的发病机制和疾病进展方面非常有用， 以及了解疫苗和药物的功效。然而，HIV-1病毒之间的遗传差异 和siv，而其他HIV-1基因如gag、pol1、vif、vpr和nef的缺失限制了siv的应用。 疫苗研究中的这些模型。理想情况下，HIV-1感染/艾滋病的良好动物模型应该是 携带HIV-1病毒的猕猴。然而，由于逆转录病毒的存在，HIV-1不能在猕猴细胞中复制 制约因素。HIV-1可以通过用SIV基因替换其附属基因来进行复制，例如 VIF、VPX、VPR和NEF，它们可以中和干扰素诱导的猕猴细胞限制因子。事实上，我们 此前有报道称，人类免疫缺陷病毒是由HIV-1NL4-3vif替换而产生的 通过SIV替换(命名为HSIV-vifNL4-3)可以在辫尾猕猴(PTM)中持续复制。然而， 感染不会导致SIV或猿人期间观察到的高峰值病毒血症和设定的病毒载量-人类 免疫缺陷病毒(SIV)感染猕猴。为了进一步适应HSIV，我们在体内进行了连续的 传代增强传染性或复制能力的传代我们进行了受感染血液的动物间转移 在3个免疫活性PTM中，开始初始接种含有CXCR4-(HSIV-vifNL4-3)的混合物 从以前感染的猕猴中恢复)和CCR5嗜性HSIV(基于PNL-AD8的HSIV-VIF衍生物 和Bru-Yu2)。有趣的是，所有的猕猴都表现出接近或超过105拷贝/毫升的病毒血症峰值和病毒 复制持续了20多周。我们已经恢复了三个嗜CXCR4的感染分子 来自第三代猕猴的克隆(IMCs)(HSIV-P3 IMCs)在整个基因组中具有有趣的突变， 或许是在暗示要适应PTMS。我们推测，HSIV-P3IMCs的进一步体内传代将 产生具有增强复制能力的致病变种。我们建议在体内进行一系列的 在较老的PTM中传代，与幼年/年轻猕猴相比，这可能支持更好的病毒复制。 由于我们只回收了嗜CXCR4的HSIV，我们还建议使用HSIV-P3内膜细胞作为骨架来开发 CCR5嗜性HSIV。这项研究的结果将为生物学的发展提供有价值的见解。 HIV-1感染相关动物模型用于疫苗预防HIV传播的临床前评价。

Abstract/Summary: Commonly used animal models of HIV-1 include infection of macaques with Simian Immunodeficiency Virus (SIV) or Simian-Human Immunodeficiency Virus (SHIV) containing HIV envelope (Env) or reverse transcriptase. These animal models have been extremely useful in understanding HIV pathogenesis and disease progression, as well as understanding the efficacy of vaccines and drugs. However, the genetic difference between HIV-1 and SIV, and the absence of other HIV-1 genes such as gag, pol, vif, vpr, and nef in SHIV limits the utility of these models in vaccine studies. Ideally, good animal model of HIV-1 infection/AIDS would be infection of macaques with HIV-1. However, HIV-1 does not replicate in macaque cells due to the presence of retroviral restriction factors. HIV-1 can be made to replicate by substituting its accessory genes with SIV genes such as vif, vpx, vpr, and nef, which can counteract interferon-induced restriction factors in macaque cells. Indeed, we have previously reported that Human-Simian Immunodeficiency Virus generated by substitution of HIV-1NL4-3 vif with SIV substitution (named HSIV-vifNL4-3) can replicate persistently in pigtail macaques (PTMs). However, infection did not result in high peak viremia and setpoint viral loads as observed during SIV or Simian-Human Immunodeficiency virus (SHIV) infection of macaques. To further adapt HSIV, we performed serial in vivo passaging to enhance infectivity or replicative capacity. We conducted animal-to-animal transfer of infected blood in 3 immunocompetent PTMs with starting initial inoculum containing a mixture of CXCR4- (HSIV-vifNL4-3 recovered from previously infected macaque) and CCR5-tropic HSIV (HSIV-vif derivative based on pNL-AD8 and Bru-Yu2). Interestingly, all the macaques showed peak viremia close to or above 105 copies/ml and virus replication persisted for more than 20 weeks. We have recovered three CXCR4-tropic infectious molecular clones (IMCs) from passage 3 macaque (HSIV-P3 IMCs) with interesting mutations throughout the genome, perhaps suggesting adaptation to PTMs. We hypothesize that further in vivo passaging of HSIV-P3 IMCs will generate pathogenic variants with enhanced replication capacity. We propose to conduct serial in vivo passaging in older PTMs, which may support better virus replication compared to juvenile/younger macaques. Since we recovered only CXCR4-tropic HSIV, we also propose to use HSIV-P3 IMCs as backbones to develop CCR5-tropic HSIV. The results from this study will provide valuable insights into development of biologically relevant animal model of HIV-1 infection for preclinical evaluation of vaccine prevention of HIV transmission.