The role of steady state broadly neutralizing antibody tissue levels in preventing distal site SHIV replication

项目摘要 尽管在HIV-1疫苗的开发上付出了巨大的努力，但仍然缺乏一种能够引起广泛中和的疫苗 足以阻断HIV感染的抗体(BNAb)。由于被动输注bNAbs的成功 希夫挑战恒河猴阻止全身感染，去年秋天启动了一项新的试验， 风险个体接受了bNAb，VRC01的静脉注射。然而，仍然存在许多问题，如 这些特殊抗体是如何提供无菌免疫的。在巴鲁奇实验室最近的一项研究中， 研究表明，在接受广中和抗体PGT121-1天静脉注射的恒河猴中， 用SIV-SF162P3经阴道攻击，攻击后1~3天有远端病毒聚集。在……里面 此外，他们发现病毒DNA和病毒RNA的比例更高，这意味着在 这些远端部位，尽管在一天前给予了广泛的中和抗体。这说明， 曾经被认为是无菌免疫并不能预防FRT和远端的早期感染 网站，尽管在10天内清除了病毒。该模型提供了一个极好的机会来了解 在FRT和远端部位急性感染后，抗体可清除病毒。在使用Cy5的初步数据中- 注射到猕猴体内的标记VRC01 IV我发现抗体需要大约1周的时间才能达到 在组织中达到稳定水平的解剖学分布，而血浆水平达到峰值的时间要早得多。 利用这个新开发的标记抗体平台，我在目标1中建议用cy5和 比较阴道内注射前7天静脉输液(稳态)和-1天静脉输液(非稳态) 用SHIVSF162P3攻击猕猴并测量雌性生殖道(FRT)和远端 在攻击后48小时和1周，病毒在现场积累。在目标2中，我将测量抗体水平 在这些远端组织中，以及在FRT中，并将其与病毒聚集进行比较。在第二部分中 为了达到这个目的，我们将观察病毒聚集的组织的转录图谱。 不存在的，与存在的抗体一起努力，以确定病毒传播的潜在路径。 最后，在目标3中，我将利用霍普实验室的一个新平台，称为巫妖报告系统，它 可识别早期传播的感染源。我将与SIV共同挑战恒河猴 假型LICH和SHIVSF162P3以及为了阐明稳态抗体分布的作用 对感染中心的数量以及病毒在全国各地的传播程度 整个FRT。在目标3的第二部分，我们将集中在这些感染的焦点上，并描述潜在的 免疫清除机制，如ADCC，由cy5标记的PGT121识别。强调的目标 本申请中概述的将提供对稳态抗体组织分布的作用的重要洞察 关于bNAbs提供的杀菌保护。

Project Summary Despite great efforts in HIV-1 vaccine development, a vaccine is still lacking that can elicit broadly neutralizing antibodies (bNAb) sufficient enough to block HIV infection. Due to the success of passive infusion of bNAbs in SHIV challenged rhesus macaques to block systemic infection, a new trial was launched this past fall where at risk individuals received an IV infusion of the bNAb, VRC01. However, there are still many questions as to how these specialized antibodies can provide sterilizing immunity. In a recent study by the Barouch lab, it was shown that rhesus macaques that got a -1 day IV infusion of the broadly neutralizing antibody PGT121, prior to intravaginal challenge with SHIV-SF162P3, had distal site virus accumulation 1-3 days after challenge. In addition, they found a higher ratio of viral DNA to viral RNA, which implies that there was active replication at these distal sites despite having been given a broadly neutralizing antibody 1 day before. This shows that what was once thought of as sterilizing immunity does not protect from early infection in the FRT and at distal sites, despite clearing the virus at 10 days. This model provides an excellent opportunity to understand how antibodies clear the virus following acute infection in the FRT and at distal sites. In preliminary data using cy5- labeled VRC01 IV injected into rhesus macaques I have found that it takes antibodies about 1 week to anatomically distribute to achieve steady state levels in the tissue, whereas plasma levels peak much earlier. Utilizing this newly developed labeled antibody platform, I propose in Aim 1 to label PGT121 with cy5 and compare -7 day IV infusion (steady state) and -1 day IV infusion (non-steady state) prior to intravaginal challenge with SHIVSF162P3 in the rhesus macaque and measure female reproductive tract (FRT) and distal site accumulation of virus at 48 hours and 1 week after challenge. In Aim 2, I will measure the antibody levels at these distal tissues as well as in the FRT and compare this with virus accumulation. In the second part of this aim, we will look at the transcriptomic profile of tissues that have virus accumulation compared to those that do not, with and with antibody present in an effort to identify a potential path of virus dissemination. Finally, in Aim 3 I will utilize a novel platform from the Hope lab known as the LICh reporter system, which allows identification of early transmitted foci of infection. I will co-challenge rhesus macaques with SIV pseudotyped LICh and SHIVSF162P3 and in order to elucidate the role of steady state antibody distribution has on the number of foci of infection as well as the extent to which the virus disseminates throughout the entire FRT. In the second part of Aim 3, we will narrow in on these foci of infection and characterize potential immune clearance mechanisms, such as ADCC, identified by the cy5-labeled PGT121. The highlighted aims outlined in this application will provide crucial insight into the role steady state antibody tissue distribution has on the sterilizing protection afforded by bNAbs.