Using adenoviral vectors to express broadly neutralizing anti-gp160 antibodies

描述（由申请人提供）：最近的估计表明，美国有110万人感染人类免疫缺陷病毒（HIV），每年有超过56，000例新感染。在这些新感染病例中，12%是静脉注射毒品（注射吸毒，共用受污染的针头）的直接结果，32%是由于与注射吸毒有关的行为（与注射吸毒者的异性恋和同性恋接触）。根据疾病控制中心的资料，注射吸毒被认为是艾滋病毒感染的第三大危险因素，其次是男男性行为者和从事无保护的异性性接触的个人。虽然吸毒预防和治疗可以减少艾滋病毒的发病率，但鉴于注射吸毒者的人数和社会经济地位，由于资金和资源不足，目前可能无法实现这一目标;因此，与此同时，对这种疾病的治疗是关键。对于美国和发展中国家的艾滋病毒感染者来说，高效抗逆转录病毒疗法（HAART）已成为治疗的主要手段。HAART的新发展使越来越多的患者出现无法检测到的病毒血症、更高的CD 4 + T细胞计数、更好的生活质量和总体生存率提高。然而，由于逃逸突变体的出现、患者难以接近和不依从、不良副作用和持续治疗的需要，许多问题仍然存在。重要的是，HAART不会影响继续产生病毒的细胞。因此，大多数接受HAART治疗的患者都有低水平的病毒血症，必须无限期地接受治疗以防止病毒反弹。为了解决这个问题，我们建议使用第一代和辅助依赖性腺病毒载体编码广泛中和抗体（bnAb）对HIV gp 160。这样的bnAb可以靶向表达抗原的感染细胞，以通过宿主免疫系统消除，并且腺病毒载体的使用提供了用于长期转基因表达的不同细胞类型的高效转导。首先，将在第一代和辅助依赖性腺病毒系统的背景下编码良好表征的bnAb。其次，我们将生产和纯化高滴度的载体颗粒储备液，用于体外表征。第三，将使用HIV感染的人源化小鼠模型在体内测试载体颗粒，以确定bnAb在减少病毒复制中的有效性。在该提案中，将针对纯化的重组bnAb平行测试载体编码的bnAb，并将第一代腺病毒与辅助依赖性腺病毒进行比较。将测试编码的bnAb的各种组合以确定靶向不同表位是否改善功效。这些目标的完成应该提供深入了解腺病毒介导的载体传递和宿主中和抗HIV抗体应答，以及提供新的载体介导的持久治疗手段的潜力，最终可能减少感染个体（包括使用药物的个体）所需的HAART的频率和持续时间。 公共卫生相关性：目前，美国有超过100万人感染艾滋病毒，每年有超过56，000例新感染[1]。艾滋病毒的治疗帮助了许多人，但并没有摆脱病毒。我们建议使用针对病毒的抗体，通过特殊载体传递，我们希望这将成为一种有效的治疗方法，甚至可能将病毒从体内清除。

DESCRIPTION (provided by applicant): Recent estimates have suggested there are 1.1 million individuals living with human immunodeficiency virus (HIV) in the United States with over 56,000 new infections arising annually. Of these new infections, 12% are a direct result of intravenous drug use (IDU, sharing of contaminated needles) and 32% are due to IDU-associated behaviors (heterosexual and homosexual contact with an IDU individual). According to the Centers for Disease Control, IDU is considered the third most important risk factor for HIV infection, surpassed by the risk groups of men who have sex with men and individuals engaging in unprotected heterosexual contact. While drug use prevention and treatment can alleviate the incidence of HIV, this may not be currently achievable due to inadequate funding and access to resources given the number and socioeconomic status of IDU individuals; thus in the meantime treatment of the disease is key. For individuals in the US and developing world who live with HIV, highly active antiretroviral therapy (HAART) has become the mainstay of treatment. New developments in HAART have given rise to increasing numbers of patients with undetectable viremia, higher CD4+ T-cell counts, better quality of life, and overall improved survival. However, many issues remain by way of emergence of escape mutants, patient inaccessibility and non-adherence, adverse side effects and the need for ongoing treatment. Importantly, HAART does not affect cells that continue to produce virus. As a result, most patients on HAART have low-level viremia and must remain on treatment indefinitely to prevent viral rebound. To therapeutically address this issue, we propose the use of first generation and helper-dependent adenoviral vectors encoding broadly neutralizing antibodies (bnAbs) against HIV gp160. Such bnAbs can target antigen-expressing, infected cells for elimination by the host immune system, and the use of adenoviral vectors gives high efficiency transduction of diverse cell types for long-term transgene expression. First, well-characterized bnAbs will be encoded in the context of first generation and helper-dependent adenoviral systems. Second, we will produce and purify high-titer stocks of vector particles for in vitro characterization. Third, vectr particles will be tested in vivo with the use of a humanized mouse model of HIV infection to determine the effectiveness of the bnAbs in reducing viral replication. In this proposal vector-encoded bnAbs will be tested in parallel against purified recombinant bnAbs, and first generation adenoviruses compared with helper-dependent adenoviruses. Various combinations of encoded bnAbs will be tested to determine if targeting different epitopes improves efficacy. The completion of these objectives should provide insight into adenoviral-mediated vector delivery and host-neutralizing anti-HIV antibody responses, as well as offer the potential for new vector-mediated means of long-lasting therapy that may eventually reduce the frequency and duration of HAART required for infected individuals, including those who use substances. PUBLIC HEALTH RELEVANCE: Currently there are over 1 million people infected with HIV in the United States, with over 56,000 new infections each year [1]. Treatment of HIV has helped many people but does not get rid of the virus. We are proposing using antibodies against the virus, delivered with special vectors, that we hope will serve as an effective treatment and may even eliminate the virus from the body.