Project 1: Establishing a robust functional cure

项目总结（项目1 -AAV表达的eCD 4-IG的稳健功能性治愈） eCD 4-IG是CD 4的前两个结构域与抗体Fc的有效且异常广泛的融合物 结构域和短的酪氨酸硫酸化辅助受体模拟肽。在恒河猴中，腺相关性 病毒（AAV）表达的eCD 4-IG介导针对SHIV-AD 8的一致且非常有效的保护， SIVmac239. eCD 4-IG还具有使其特别可用于建立功能性治愈的性质， 恒河猴和人类。这些包括其效力，广度，逃脱难度，低 当由AAV表达时的免疫原性、由AAV的一致表达、有效的内在ADCC活性，以及 与血清抗体协同介导ADCC。这些特性允许eCD 4-IG绕过两个 与使用AAV表达的抗体建立功能性治愈相关的主要问题，即 免疫清除和病毒逃逸。在初步的数据中，我们表明AAV表达的eCD 4-IG可以在细胞内表达。 在6只猕猴中5只中抑制SHIV-AD 8复制超过一年。然而，我们也表明， 当与项目2中描述的“猴子”相比时，这种抑制不太稳健，这意味着 在大多数eCD 4-Ig抑制的动物中观察到一致的病毒“起泡”。因为迈阿密 在这些表达eCD 4-Ig的猴子中观察到的总抗体量的大约10倍， 在猕猴中，我们假设eCD 4-IG的更高表达将导致更稳健的功能性治愈。 因此，本项目的目标是增加eCD 4-IG的AAV介导的表达，以建立稳健的免疫原性。 在SHIV-AD 8和SIVmac 239感染的猕猴中进行功能性治疗，以放大这些猕猴中的ADCC活性。 通过刺激宿主抗体对eCD 4-IG暴露的表位的应答， 一致的平台，将允许评估延迟逆转剂，并询问是否长期 eCD 4-IG自身的表达可影响病毒库。这些研究将改善和帮助 了解在人类中建立类似功能性治疗的可行方法。

PROJECT SUMMARY (Project 1 – Robust functional cures with AAV-expressed eCD4-Ig) eCD4-Ig is a potent and exceptionally broad fusion of the first two domains of CD4 to an antibody Fc domain and a short tyrosine-sulfated coreceptor-mimetic peptide. In rhesus macaques, adeno-associated virus (AAV)-expressed eCD4-Ig mediates consistent and very effective protection against SHIV-AD8 and SIVmac239. eCD4-Ig also has properties that make it especially useful for establishing a functional cure in rhesus macaques and perhaps in humans. These include its potency, breadth, difficulty-of-escape, low immunogenicity when expressed by AAV, consistent expression by AAV, potent intrinsic ADCC activity, and collaboration with serum antibodies to mediate ADCC. These properties allow eCD4-Ig to circumvent two major problems associated with using AAV-expressed antibodies to establish functional cures, namely immune clearance and viral escape. In preliminary data we show that AAV-expressed eCD4-Ig can suppress replication of SHIV-AD8 for more than a year in 5 of 6 macaques. However we also show that, when compared to the “Monkey monkey” described in Project 2, this suppression was less robust, meaning that consistent ‘blipping’ of virus was observed in most eCD4-Ig-suppressed animals. Because the Miami monkey expresses roughly 10 times the amount of total antibody observed in these eCD4-Ig-expressing macaques, we hypothesize that greater expression of eCD4-Ig will result in more robust functional cures. The goals of this project are thus to increase AAV-mediated expression of eCD4-Ig, to establish robust functional cures in SHIV-AD8 and SIVmac239-infected macaques, to amplify the ADCC activities in these macaques by stimulating host antibody responses to epitopes unmasked by eCD4-Ig, to establish a consistent platform that will allow for evaluation of latency reversing agents, and to ask whether long-term expression of eCD4-Ig by itself can impact the viral reservoir. These studies will improve and help understand a viable approach to establishing similar functional cures in humans.