CHARACTERIZATION OF HIV-1 ANTIBODY RESPONSES IN CHRONICALLY INFECTED WOMEN

描述（由申请人提供）： HIV特异性中和抗体（Nabs）已被证明可以在猕猴模型中保护免受SHIV感染，这表明具有足够效力的Nabs可以在人类中提供一些针对HIV感染的保护。鉴于全球流行的HIV毒株之间存在相当大的遗传和抗原多样性，至关重要的是，保护性Nab应答不仅表现出对一种特定挑战病毒的效力，而且还表现出跨亚型宽度和中和在高发地区传播的流行变体的能力。最近从艾滋病毒感染者中分离出了几种具有这些特征的Nab。这些令人兴奋的发现证明了人类免疫系统能够激发Nab对HIV抗原具有广泛特异性的反应，并且新的Nab已经被用于研究被动免疫保护。然而，这些广泛的抗体是从感染多年的个体中分离出来的，是广泛的体细胞超突变的结果-这是一个使用现有技术无法用疫苗免疫原模拟的过程。因此，一个关键的问题是是否可以在感染的早期阶段引起不需要这种长期抗原刺激的广泛Nab。我们已经确定了一个人谁有一个艾滋病毒特异性的Nab反应与显着的跨亚型宽度在艾滋病毒感染后6个月。我们还鉴定了由于重复感染而具有异常广泛和有效的精英中和活性的个体。我们假设这些个体的Nab反应与先前研究中检查的感染持续时间较长的单一感染个体不同，包括体细胞超突变的程度。在这里，我们建议在这些独特的个人，这将包括映射的NAb特异性和克隆和表征相应的Nabs的Nab的反应。此外，我们将利用这些人在感染艾滋病毒和/或重复感染之前获得的库存样本来检查艾滋病毒特异性Nab反应的演变-这是一种在任何先前研究中都不可能的方法。我们还将继续筛选在感染早期就产生广泛Nab反应的人群。这些研究旨在揭示开发广泛有效的HIV特异性Nab的新途径。

DESCRIPTION (provided by applicant): HIV-specific neutralizing antibodies (Nabs) have been shown to protect against SHIV infection in the macaque model, suggesting that Nabs of sufficient potency could provide some protection against HIV infection in humans. Given the considerable genetic and antigenic diversity among global circulating strains of HIV, it is critica that protective Nab responses exhibit not only potency for one particular challenge virus, but also cross-subtype breadth and the capacity to neutralize circulating variants that are spreading in high incidence areas. Several Nabs with these characteristics have recently been isolated from HIV-infected individuals. These exciting discoveries demonstrate the capacity of the human immune system to elicit Nabs with broad specificity in response to HIV antigens, and the new Nabs are already being exploited to study passive immune protection. However, these broad antibodies, which were isolated from individuals who had been infected for many years, are the result of extensive somatic hypermutation -- a process that is not possible to mimic with a vaccine immunogen using current technologies. Thus, a critical question is whether broad Nabs that do not require such long-term antigenic stimulation can be elicited at earlier stages in infection. We have identified an individual who has a HIV-specific Nab response with significant cross-subtype breadth at 6 months after HIV infection. We have also identified individuals with exceptionally broad and potent elite neutralizing activity as a result of superinfection. We hypothesize that the Nab responses in these individuals will be distinct from those of singly-infected individuals with longer duration of infection examined in prior studies, including in the extent of somatic hypermutation. Here we propose to characterize the Nab responses in these unique individuals, which will include mapping the NAb specificity and cloning and characterizing the corresponding Nabs. In addition, we will take advantage of banked samples available from these individuals starting before their HIV infection and/or superinfection to examine the evolution of the HIV-specific Nab response -- an approach that has not been possible in any prior studies. We will also continue to screen our cohort for individuals who develop broad Nab responses very early in their infection. These studies are designed to uncover novel pathways to developing broad and potent HIV-specific Nabs.