Project 1: Establishing a robust functional cure

项目摘要(项目1--AAV表达的eCD4-Ig的强健功能疗法) ECD4-Ig是一种将前两个结构域与抗体Fc进行有效和异常广泛的融合 结构域和一个短的酪氨酸硫化的辅受体模拟肽。在恒河猴中，腺相关 病毒(AAV)表达的eCD4-Ig介导了对SHV-AD8和SIV-AD8的一致和非常有效的保护 SIVmac239。ECD4-Ig还具有使其特别适用于建立功能性治疗的特性 恒河猴，也许还有人类。这些因素包括其效力、广度、逃逸难度、低 AAV表达时的免疫原性，AAV表达的一致性，强大的内在ADCC活性，以及 与血清抗体协同介导ADCC。这些特性允许eCD4-Ig绕过两个 与使用AAV表达的抗体建立功能性治疗相关的主要问题，即 免疫清除和病毒逃逸。在初步数据中，我们显示AAV表达的eCD4-Ig可以 在6只猕猴中，有5只在一年以上的时间内抑制了SIV-AD8的复制。然而，我们也表明， 与项目2中描述的“猴子”相比，这种抑制不那么强烈，这意味着 在大多数eCD4-Ig被抑制的动物中，都观察到了病毒的持续“跳跃”。因为迈阿密 Money表达的总抗体量大约是eCD4-Ig表达的总抗体的10倍 对于猕猴，我们假设eCD4-Ig的更大表达将导致更强大的功能治疗。 因此，该项目的目标是增加AAV介导的eCD4-Ig的表达，建立稳健的 对感染SIV-AD8和SIVmac239的猕猴进行功能性治疗，以放大这些猕猴的ADCC活性 通过刺激宿主抗体对eCD4-Ig揭示的表位的反应，建立一种 一致的平台，将允许评估延迟反转剂，并询问是否长期 ECD4-Ig的表达本身就会影响病毒库。这些研究将改善和帮助 了解一种可行的方法，在人类身上建立类似的功能疗法。

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.