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110万人携带人类免疫缺陷病毒(HIV)，每年新增感染人数超过56,000人。在这些新感染中，12%是静脉吸毒(注射吸毒者，共用受污染的针头)的直接结果，32%是与注射吸毒者相关的行为(与注射吸毒者的异性或同性恋接触)造成的。根据疾病控制中心的数据，注射毒品被认为是艾滋病毒感染的第三大风险因素，超过了男男性行为的风险群体和从事无保护措施的异性接触的个人。虽然药物使用预防和治疗可以减少艾滋病毒的发病率，但由于注射吸毒者的人数和社会经济地位，由于资金不足和获得资源的机会不足，目前可能无法实现这一目标；因此，在此期间治疗这种疾病是关键。对于美国和发展中国家的艾滋病毒携带者来说，高效抗逆转录病毒疗法(HAART)已成为主要的治疗方法。HAART的新进展导致越来越多的患者患有无法检测到的病毒血症，更高的CD4+T细胞计数，更好的生活质量，以及整体改善的存活率。然而，由于逃逸突变的出现、患者无法接触和不坚持、不良副作用以及需要持续治疗，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，接受HAART的大多数患者都有低水平的病毒血症，必须无限期地继续治疗，以防止病毒反弹。为了从治疗上解决这个问题，我们建议使用第一代和辅助依赖的腺病毒载体，编码针对HIV gp160的广泛中和抗体(BNAbs)。这种bNAbs可以靶向抗原表达的受感染细胞，被宿主免疫系统清除，使用腺病毒载体可以高效地转导不同类型的细胞，以实现长期转基因表达。首先，特征良好的bNAbs将在第一代和辅助子依赖腺病毒系统的背景下编码。其次，我们将生产和纯化用于体外鉴定的高滴度载体颗粒。第三，将使用HIV感染的人源化小鼠模型在体内测试Vectr颗粒，以确定bNAbs在减少病毒复制方面的有效性。在这项建议中，载体编码的bNAbs将与纯化的重组bNAbs进行平行测试，并将第一代腺病毒与辅助依赖型腺病毒进行比较。将对编码的bNAbs的各种组合进行测试，以确定针对不同表位是否会提高疗效。这些目标的完成将提供对腺病毒介导的载体传递和宿主中和抗HIV抗体反应的洞察力，并为新的载体介导的长期治疗方法提供可能性，最终可能减少感染个体所需的HAART的频率和持续时间，包括那些使用药物的人。 公共卫生相关性：目前美国有100多万人感染艾滋病毒，每年新增感染者超过56,000人[1]。艾滋病毒的治疗帮助了许多人，但并没有摆脱病毒。我们建议使用通过特殊载体传递的针对病毒的抗体，我们希望这种抗体将成为一种有效的治疗方法，甚至可能从体内消除病毒。

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.