Optimizing Plantibodies for Trapping HIV and HSV in Cervicovaginal Mucus

项目随附资料（见说明）： 对于阴道传播，病毒必须穿透粘液分泌物到达靶细胞;我们最近发现，单纯疱疹病毒（HSV）和HIV很容易通过人类宫颈阴道粘液扩散。免疫系统产生的大多数抗体（Ab）分泌到粘液中（而不是血液或淋巴），局部IgG提供了强大的保护，以抵御阴道病毒的挑战。除了众所周知的抗体功能（例如，中和、补体激活、调理素作用），IgG的一个重要但很少被认识到的效应子功能是将病毒捕获在粘液中。与病毒表面结合的IgG可以在病毒和粘液凝胶之间形成多个低亲和力粘附交联。足够数量的这些低亲和力交联，可能在亚中和IgG浓度下，可能将病毒永久捕获在粘液凝胶中。我们的初步观察表明，非常低浓度的特异性IgGI可以捕获HSV-1和病毒样颗粒，否则它们会迅速穿透粘液凝胶。捕获减少了到达靶细胞的病毒通量，并通过额外的保护机制促进灭活和清除。在病毒到达靶细胞之前将其捕获在粘液中可能对于防止病毒感染至关重要，这些病毒一旦建立，就会导致无法治愈的感染。最具保护性的抗体很可能是那些不仅能通过阻断病毒进入靶细胞来中和病毒体，而且能高效地将病毒体捕获在粘液中的抗体。粘液中这种潜在的IgG捕获功能在很大程度上还没有被认识到，因为大多数IgG活性的研究还没有在粘液中进行。因此，迄今为止开发的所有单克隆抗体（MAb）都是在不考虑粘液中的这种免疫功能的情况下开发的。在这个提议中，我们试图确定最有效的植物产生的抗病毒IgG（PAb），用于捕获人类宫颈阴道粘液以及粘液和精液混合物中的HSV和HIV（目的1）。我们还将比较通过阴道环与薄膜递送的PAb的分布，以确定在最低PAb剂量下完全覆盖敏感上皮表面的递送方法（目标2）。基于目标1和2，我们将测试体内对阴道HSV攻击的保护，以及评估PAb和递送载体的安全性（目标3）。

PROJECT SUIVIMARY (See Instructions): For vaginal transmission, viruses must penetrate mucus secretions to reach target cells; we recently found that Herpes Simplex Virus (HSV) and HIV readily diffuses through human cervicovaginal mucus. Most antibodies (Ab) produced by the immune system are secreted into mucus (not blood or lymph), and topical IgG provides robust protection against vaginal viral challenges. In addition to well-known antibody functions (e.g., neutralization, complement activation, opsonization), an important yet little recognized effector function of IgG is to trap viruses in mucus. IgG bound to a virus surface may form multiple low-affinity adhesive crosslinks between the virus and the mucus gel. A sufficient number of these low-affinity crosslinks, possibly at sub-neutralizing IgG concentrations, may permanently trap the virus in the mucus gel. Our pilot observations indicate that remarkably low concentrations of specific IgGI can trap HSV-1 and virus-like particles that otherwise rapidly penetrate mucus gels. Trapping reduces the flux of virus that reaches target cells, and facilitates inactivation and clearance by additional protective mechanisms. Trapping viruses in mucus before they can reach target cells is likely essential to protect against viruses that, once established, cause incurable infections. It is likely that the most protective antibodies will be those that not only neutralize virions by blocking viral entry into target cells, but also are highly effective at trapping virions in mucus. This potential IgG trapping function in mucus has been largely unrecognized because most studies of IgG activity have not been performed in mucus geis. Hence, all monoclonal antibodies (MAbs) developed to date has been developed without considering this immune function in mucus. In this proposal, we seek to identify themost potent plant-produced anti-viral IgGs (PAbs) for trapping HSV and HIV in human cervicovaginal mucus as well as in mixtures of mucus and semen (Aim 1). We will also compare the distribution of PAbs delivered by vaginal ring vs. film to identify the delivery method that provides complete coverage of susceptible epithelial surface at the lowest PAb dose (Aim 2). Based on Aims 1 & 2, we will test for protection against vaginal HSV challenge in vivo, as well as evaluate the safety of the PAbs and delivery vehicle (Aim 3).