Modeling the molecular evolution of SIV to HIV using humanized mice

项目摘要/摘要 由艾滋病毒-1和艾滋病毒-2(程度较轻)引起的艾滋病大流行导致超过3500万人死亡 世界范围内，这两种病毒现在都深深地扎根于人类人口中。这些罪魁祸首是如何产生的 在20世纪期间，从长期存在的良性古代SIV病毒株仍然是一个谜。几个 已经提出了一些假设，包括简单的人畜共患传播，然后是现代人 迁徙，传播其他孤立的农村疾病，或先祖不经意间连续通过 人类体内的病毒导致毒力增加。一个实验系统，可以测试其中的一些 直到最近，假说一直都很缺乏。随着人源化小鼠(人鼠)的出现，这种小鼠拥有一种 移植了人类免疫系统，现在有可能解决一些关键问题 围绕着一种存在了数千年的非人类灵长类原生逆转录病毒是如何跳过 物种障碍和进化导致了目前的人类大流行。在我们的实验室和其他地方工作 已经建立了新一代人小鼠，可以持续产生人类T细胞，B细胞， 巨噬细胞和树突状细胞从头开始，对感染HIV-1和HIV-1非常敏感- 2引起慢性病毒血症和典型的艾滋病的CD4T细胞丧失。因此，我们现在处于一个独特的位置 直接评估祖先SIV毒株对人类病毒传播、发病机制和 生理上相关的活体人类代孕系统的进化。我们研究的主要目的是 利用这一独特的体内模型进行黑猩猩SIVcpz和黑猩猩SIVsm病毒的连续传代 毒株，分别是HIV-1和HIV-2的前体，并决定遗传和表型变化 对艾滋病毒病毒株的出现负有责任。我们最近通过以下方式得出了有希望的初步数据 在小鼠体内成功生长和适应SIVsm和SIVcpz。第二次通过的序列数据 SIVsm显示gp41有固定突变，第一代SIVcpz显示出序列变化 病毒进化的结果。这些新出现的数据表明，我们拟议的研究是可行的，并将达到 令人兴奋的目标是了解这两种艾滋病毒出现的遗传基础，从而揭示 这是一个长期存在的谜团。 在这项工作中，我们将在人小鼠体内连续传代SIVcpz和SIVsm，以获得人类适应病毒 分别代表完全进化的HIV-1和HIV-2毒株，这是关键 致病属性，导出序列数据以识别适应性序列变化并评估关键的 克服人类限制因素中的基因组变化，如系链蛋白。 为了进行这些有希望的研究，我们组建了一个有成就和热情的合作者团队。 普雷斯顿·马克思博士(杜兰大学)、谢尔比·奥康纳博士和大卫·埃文斯博士(威斯康星大学)、弗朗索瓦·维林格博士 (路易斯安那州新伊比利亚研究所)，Brandon Keele(NCI，Frederick)，Mark Stenglein和Ramesh Akina(科罗拉多州立大学)参与互补领域的工作，以便在该项目中发挥协同作用。

Project Summary / Abstract The AIDS pandemic caused by HIV-1 and to a lesser extent by HIV-2 resulted in more than 35 million deaths worldwide, with both these viruses now deeply entrenched in the human population. How these culprits arose during the 20th century from the long-preexisting benign ancient SIV viral strains is still a mystery. Several hypotheses have been put forward that include simple zoonotic transfer followed by spread, modern human migration spreading an otherwise isolated rural disease or inadvertent serial passage of the progenitor viruses in humans resulting in increased virulence. An experimental system that can test some of these hypotheses has been lacking until recently. With the advent of humanized mice (hu-mice) that harbor a transplanted human immune system, it has now become possible to address some key questions surrounding how a retrovirus native to non-human primates that existed through the millennia jumped the species barrier and evolved to give rise to the current human pandemic. Work in our laboratories and others have established a new generation of hu-mice that continuously generate human T cells, B cells, macrophages and dendritic cells de novo, and that are exquisitely sensitive to infection with HIV-1 and HIV- 2 giving rise to chronic viremia and CD4 T cell loss typical of AIDS. Thus, we are now in a unique position to directly evaluate the potential of ancestral SIV strains for human viral transmission, pathogenesis and evolution in a physiologically relevant in vivo human surrogate system. The primary aim of our studies is to exploit this unique in vivo model for serial passage of chimpanzee SIVcpz and sooty mangabey SIVsm viral strains, the progenitors of HIV-1 and HIV-2, respectively, and determine the genetic and phenotypic changes responsible for the emergence of the HIV viral strains. We recently derived promising preliminary data by successfully growing and adapting SIVsm and SIVcpz in hu-mice. Sequence data on the 2nd passage of SIVsm showed fixed mutations in gp41 and the 1st passage SIVcpz has shown sequence changes indicative of viral evolution. These emerging data point to the feasibility of our proposed studies and to reaching the exciting goal of understanding the genetic basis for emergence of both HIV types and thus shedding light on a long-standing mystery. In this work, we will serially passage SIVcpz and SIVsm in vivo in hu-mice to derive human adapted viruses that potentially represent fully evolved strains of HIV-1 and HIV-2 respectively, characterize the key pathogenic attributes, derive sequence data to identify adaptive sequence changes and assess the critical genomic changes in overcoming human restriction factors such as tetherin. To conduct these promising studies, we assembled an accomplished and enthusiastic team of collaborators Drs. Preston Marx (Tulane), Shelby O'Connor and David Evans (University of Wisconsin), Francoise Villinger (New Iberia Research Institute, Louisiana), Brandon Keele (NCI, Frederick), Mark Stenglein and Ramesh Akkina (Colorado State University) involved in complementary areas of work to synergize in this project.