Penile transmission and neutralization of pathogenic SIVsmm

描述(由申请人提供)：本提案侧重于阴茎获得致病性SIVsmm感染，因为这一传播途径占全球艾滋病毒-1大流行的近一半，并与其他粘膜传播途径进行了比较，研究不足。阐明SIV/HIV传播的瓶颈以及阴茎上皮和粘膜表面成功感染的分子和细胞机制可能有助于设计有效的疫苗。我们的实验室已经为实现这些目标迈出了重要的一步，通过开发和验证一种实验策略来识别、列举和分子克隆传播/创始人HIV-1和SIV基因组，这些基因组是导致生产性感染的(Keele 2008；Keele 2009；Salazar 2009；Stone 2010；Bar 2010；Li 2010a，b)。在这个项目中，我们将检验以下假设：遗传多样性的、恒河猴适应的致病性SIVsmm病毒将通过无创阴茎接种来有效地感染印度恒河猴，并导致持续的复制和致病性。在这种传播模型中，对传播病毒/方正病毒的分析将揭示粘膜瓶颈的程度，以及中和抗体和结合抗体对阻断感染的影响。对这一假说的检验将提供对阴茎SIV/HIV感染的生物学、SIV/HIV在急性感染期间的高传播性以及在慢性感染中抗SIV/HIV抗体对正向传播的相对保护作用的机械性见解。具体目标是：(I)通过从急性感染血浆中无创接种遗传分化的、猕猴适应的致病SIVsmm病毒来有效地感染印度恒河猴；(Ii)通过单基因组扩增鉴定这些动物的传播/创始病毒的分子克隆；(Iii)确定急性感染动物的血浆中是否含有比慢性期感染相同动物的血浆更具传染性和传播性的病毒；(Iv)与静脉接种相比，定量表征阴茎传播的瓶颈；以及(V)确定慢性期血浆是否含有防止阴茎或静脉感染病毒的SIV特异性抗体。除了对阴茎传播和“急性到急性”感染的潜在机制的新的科学见解外，该项目的一个关键成果将是8个新的阴茎传播/创始病毒的分子克隆，这些分子克隆代表了广泛不同的SIVsmm遗传谱系，可用作潜在的疫苗挑战股票，并用于SIV传播生物学的进一步研究。 公共卫生相关性(由申请者提供)：人们普遍认为，消毒艾滋病毒或SIV疫苗将需要中断最早的感染事件序列。该项目将利用遗传分化的致病SIVsmm病毒开发一种新的恒河猴阴茎传播模型，并将表征粘膜瓶颈并确定早期感染事件对抗体中介保护的脆弱性。

DESCRIPTION (provided by applicant): This proposal focuses on penile acquisition of pathogenic SIVsmm infection since this transmission route accounts for nearly half of the global HIV-1 pandemic and has been understudied in comparison with other mucosal routes of transmission. Elucidation of the bottleneck to SIV/HIV transmission and the molecular and cellular mechanisms underlying successful infection at epithelial and mucosal surfaces of the penis could be instrumental in the design of effective vaccines. Our laboratories have taken significant steps toward addressing these goals by developing and validating an experimental strategy with which to identify, enumerate, and molecularly clone transmitted/founder HIV-1 and SIV genomes that are responsible for productive infection (Keele 2008; Keele 2009; Salazar 2009; Stone 2010; Bar 2010; Li 2010a,b). In this project, we will test the following hypothesis: Genetically-diverse, rhesus macaque-adapted, pathogenic SIVsmm viruses will productively infect Indian rhesus macaques by atraumatic penile inoculation and lead to persistent replication and pathogenicity. Analysis of transmitted/founder viruses in this transmission model will reveal the extent of the mucosal bottleneck and the impact of neutralizing and binding antibodies on blocking infection. A test of this hypothesis will provide mechanistic insights into the biology of penile SIV/HIV acquisition, the high transmissibility of SIV/HIV during the acute infection period, and the relative protective effect of anti-SIV/HIV antibodies in chronic infection on forward transmission. Specific aims are: (i) To productively infect Indian rhesus macaques by atraumatic penile inoculation of genetically-divergent, macaque-adapted, pathogenic SIVsmm viruses from acute infection plasma; (ii) To identify by single genome amplification and to molecularly clone transmitted/founder viruses from these animals; (iii) To determine if plasma from acutely infected animals contains virus that is more infectious and transmissible on a per virion basis than plasma from the same animals in chronic phase infection; (iv) To characterize quantitatively the bottleneck to penile transmission compared with intravenous inoculation; and (v) To determine if chronic phase plasma contains SIV-specific antibodies that prevent penile or intravenous virus acquisition. A key deliverable of this project, in addition to new scientific insights into penile transmission and mechanisms underlying 'acute- to-acute' infection, will be 8 new molecular clones of transmitted/founder viruses resulting from penile acquisition that represent widely divergent SIVsmm genetic lineages for use as potential vaccine challenge stocks and in further studies of SIV transmission biology. PUBLIC HEALTH RELEVANCE (provided by applicant): It is widely believed that a sterilizing HIV or SIV vaccine will need to interrupt the earliest sequence of infection events. This project will develop a new rhesus macaque penile transmission model using genetically-divergent, pathogenic SIVsmm viruses and it will characterize the mucosal bottleneck and determine the vulnerability of early infection events to antibody-mediated protection.