Mucosal transmission and pathogenicity of novel SIVsmm virus strains

研制有效的艾滋病疫苗仍然是艾滋病毒研究的最高优先事项之一。艾滋病毒发病机制、疫苗设计和抗逆转录病毒治疗的研究需要适当的动物模型。然而，现有的SIV/猕猴模型有很大的局限性，因为(i) SIV - mac原型株致病性太强，（ii）不代表粘膜传播病毒，（iii）已经在体外和体内广泛传代。我们最近发现了一大批新的SIVsmm毒株，它们在遗传多样性上反映了HIV-1 M组病毒。此外，初步的体内实验结果表明，这些SIVsmm毒株感染RMs更接近地再现了人类HIV-1的自然历史。因此，在这个HIVRAD联盟中，我们建议使用这些新的SIVsmm毒株来产生新的（分子克隆的）攻击病毒，用于艾滋病疫苗和发病机制的研究。项目1将采用剂量递增策略，通过静脉注射（iv）、直肠内注射（ir）和阴道内注射（ivag）途径，用具有遗传多样性的SIVsmm菌株感染21只印度恒河猴（RMs）。然后，项目2将采用单基因组扩增（SGA）技术从所有这些动物中推断并随后克隆传播/创始人（T/F）病毒。在详细的体外鉴定之后，将选择一部分克隆进行体内竞争（n=18）和发病机制（n=8）研究，这些研究将由项目1进行。

The development of an effective AIDS vaccine remains one of the highest priorities in HIV research. Studies of HIV pathogenesis, vaccine design and antiretroviral treatments require an appropriate animal model. However, the existing SIV/macaque model has major limitations since (i) prototypic SIVmac strains are too pathogenic, (ii) do not represent mucosally transmitted viruses, and (iii) have been extensively passaged in vitro and in vivo. We have recently identified a large set of new SIVsmm strains which mirror HIV-1 group M viruses in their genetic diversity. Moreover, preliminary in vivo results show that infection of RMs with these SIVsmm strains more closely reproduces the natural history of HIV-1 in humans. Within this HIVRAD consortium, we thus propose to use these new SIVsmm strains to generate new (molecularly cloned) challenge viruses for AIDS vaccine and pathogenesis studies. Project 1 will use a dose-escalation strategy to infect 21 Indian rhesus macaques (RMs) with genetically diverse SIVsmm strains using intravenous (iv), intrarectal (ir) and intravaginal (ivag) routes. Project 2 will then employ single genome amplification (SGA) techniques to infer, and subsequently clone, transmitted/founder (T/F) virus(es) from all of these animals. Following detailed in vitro characterization, a subset of clones will be selected for in vivo competition (n=18) and pathogenesis (n=8) studies which will be performed by Project 1. Specific Aims include: 1. To generate high titer plasma stocks of genetically divergent SIVsmm strains without in vitro adaptation for subsequent mucosal and intravenous transmission studies. 2. To infect RMs by intravenous, intrarectal and intravaginal routes with physiologically relevant doses of genetically divergent SIVsmm strains to allow for the identification of transmitted founder (T/F) viruses: 3.; To identify SIVsmm clones with, preferential mucosal transmissibility and replication fitness by conducting an in vivo competition experiment. 4. To characterize the selected SIVsmm clones for in vivo replication kinetics, pathogenicity and suitability as vaccine challenge stocks. We expect these studies to generate new infectious molecular clones of SIVs with biological properties that more faithfully recapitulate the transmission, pathogenic and diversity of HIV-1 in humans.