An AAV Approach to Treating HIV

项目总结 我们最近发表了我们的研究，表征了eCD4-Ig。ECD4-Ig是一种类似抗体的艾滋病毒 一种进入抑制物，它将一种硫化的CCR5模拟肽与CD4-Ig的C末端融合。基于 中和试验数据，eCD4-Ig比一些描述得最好的更广泛且同样有效 迄今为止，HIV-1广泛中和抗体。ECD4-Ig中和包括38株HIV-1在内的所有测试毒株 耐3BNC117或NIH45-46、HIV-2、SIVmac239、SIVmac251的菌株，以及使用CXCR4 AS的菌株 它们的共同受体。CCR5模拟肽的加入使eCD4-Ig对 细胞表面表达的HIV-1包膜病毒以及亚中和水平引起的有限病毒增强 CD4-Ig。使用腺相关病毒(AAV)载体，我们已经证明了恒河猴形式的eCD4-Ig 可以在四只恒河猴体内表达一年多，对动物没有伤害。RH- ECD4-Ig蛋白滴度达到了保护所有四只猕猴免受多种SIV-AD8感染的水平 挑战高达AID50(动物感染剂量50)的16倍。我们确实观察到了一个可测量的反- 对表达的rh-eCD4-Ig蛋白的转基因反应，但反应不接近水平 可对抗AAV传播的HIV-1抗体。然而，即使是相对温和的免疫反应 转基因可以限制抑制物在体内的效果。有了这些令人鼓舞的数据，这项提议 试图回答两个主要问题：(1)AAV表达的eCD4-Ig能否用于治疗 在感染SHV的猕猴中维持病毒抑制？(2)干扰素诱导的miRNAs能否调节 来自AAV载体的转基因表达以限制宿主对转基因的免疫反应？与 使用eCD4-Ig作为抗逆转录病毒治疗替代品的主要目标，回答了这两个问题 问题将继续建立在AAV提供的eCD4-Ig的安全性和有效性以及实现 AAV载体用于基因治疗的全部潜力。

PROJECT SUMMARY We have recently published our research that characterizes eCD4-Ig. eCD4-Ig is an antibody-like HIV entry inhibitor that fuses a sulfated CCR5-mimetic peptide to the C-terminus of CD4-Ig. Based on neutralization assay data, eCD4-Ig is broader than and equally potent as some of the best described HIV-1 broadly neutralizing antibodies to date. eCD4-Ig neutralized all isolates tested including 38 HIV-1 isolates resistant to 3BNC117 or NIH45-46, HIV-2, SIVmac239, SIVmac251, and isolates that use CXCR4 as their coreceptor. The addition of the CCR5-mimetic peptide allowed eCD4-Ig to have higher affinity for cell surface-expressed HIV-1 Env and also limited viral enhancement caused by sub-neutralizing levels of CD4-Ig. Using adeno-associated virus (AAV) vectors, we have shown that a rhesus form of eCD4-Ig can be expressed in four rhesus macaques for over one year with no harm to the animals. The rh- eCD4-Ig protein titers were at levels that protected all four macaques from multiple SHIV-AD8 challenges up to 16-times the AID50 (Animal Infectious Dose 50). We did observe a measurable anti- transgene response to the expressed rh-eCD4-Ig protein, but the response was not near the levels seen against AAV-delivered HIV-1 antibodies. Yet, even a relatively modest immune response to the delivered transgene can limit the inhibitor’s efficacy in vivo. With these encouraging data, this proposal seeks to answer two main questions: (1) Can AAV-expressed eCD4-Ig be used as a therapy to maintain viral suppression in SHIV infected macaques? (2) Can interferon-induced miRNAs regulate transgene expression from AAV vectors to limit the host immune response to the transgene? With the primary goal of using eCD4-Ig as an alternative to antiretroviral therapies, answering these two questions will continue to build on the safety and efficacy of AAV-delivered eCD4-Ig as well as realizing the complete potential of AAV vectors used for gene therapy.