An AAV Approach to Treating HIV

项目摘要 我们最近发表了我们的研究，表征eCD 4-IG。eCD 4-IG是一种抗体样HIV 将硫酸化CCR 5模拟肽融合到CD 4-IG C末端的进入抑制剂。基于 根据中和试验数据，eCD 4-IG比一些最佳描述的免疫球蛋白更广泛，并且效力相同。 HIV-1广泛中和抗体。eCD 4-IG中和了所有检测分离株，包括38株HIV-1 对3BNC 117或NIH 45 -46、HIV-2、SIVmac 239、SIVmac 251耐药的分离株，以及使用CXCR 4作为 它们的共同受体CCR 5模拟肽的加入使得eCD 4-IG对CCR 5具有更高的亲和力。 细胞表面表达的HIV-1 Env，以及由亚中和水平引起的有限的病毒增强 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eCD 4-IG 可在4只恒河猴体内表达1年以上，对动物无危害。RH- eCD 4-IG蛋白滴度处于保护所有四只猕猴免受多种SHIV-AD 8感染的水平 AID 50（Animal Infectious Dose 50）的16倍。我们确实观察到了一个可测量的反- 转基因对表达的rh-eCD 4-IG蛋白有应答，但应答水平远低于 针对AAV递送的HIV-1抗体观察到。然而，即使是相对温和的免疫反应， 递送的转基因可限制抑制剂在体内的功效。有了这些令人鼓舞的数据， 旨在回答两个主要问题：（1）腺相关病毒表达的eCD 4-IG能否用作治疗方法 在SHIV感染的猕猴中维持病毒抑制？(2)干扰素诱导的miRNAs能调节 从AAV载体的转基因表达，以限制宿主对转基因的免疫应答？与 使用eCD 4-IG作为抗逆转录病毒疗法的替代方案的主要目标， 问题将继续建立在腺相关病毒（AAV）递送的eCD 4-IG的安全性和有效性以及实现的基础上 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.