Peptide Vaccines from Neutralizing Antibodies 2F5 & 2G12

描述：(改编自申请者摘要)没有一种疫苗处于试验阶段 今天诱导的抗体(Abs)可以中和多种初级分离株 人类免疫缺陷病毒1型(HIV-1)。三种人类抗体 中和广泛的HIV-1初级分离株已被克隆：单抗BL2 和2G12和2F5。用这些单抗进行被动免疫会产生灭菌作用 致病性新城疫病毒对恒河猴的免疫保护和黏膜攻击 菌株。这支持了一种假设，即一种刺激细胞的活性疫苗 产生与单抗BL2、2F5和2G12相似或相同的单抗应 提供有效的预防艾滋病毒-1感染的措施。我们建议开发 并优化疫苗先导肽，以诱导产生 中和抗体的性质(可能还有结构)类似于 单抗2F5和2G12。我们已经确定了这两种物质的独特多肽配体 现在建议使用噬菌体展示的组合来优化它们 技术和合成肽。优化后的多肽将被测试为 结合疫苗中的免疫原。利用之前的R21资金，我们开发了B2.1， 与单抗BL2特异性和选择性结合的同源二聚体多肽(它是 现在处于优化的高级阶段)，并已准备好共轭化合物并开始 将其作为疫苗进行测试。到目前为止，我们已经证明了B2.1肽可以产生 在小鼠中用作结合疫苗时，可产生强大的抗肽抗体效价，以及 也许，与gp20的弱交叉反应(这有待进一步证实)。 测试)。B2.1似乎也在猪的血清中发现了类似BL2的反应性 一些HIV-1感染者。我们计划对2G12和2F5引线进行类似的工作； 它们只是处于非常早期的发展阶段。通过功能 和结构研究，我们将探索单抗反应性的基础 与其相对应的多肽，以设计高亲和力的多肽 配基。我们将测试这些多肽的诱导性 HIV-1-交叉反应抗体在小鼠中遵循两种免疫策略， 异种小鼠动物和猕猴；然后将测试免疫血清 HIV-1结合抗体的存在和中和活性。我们还将 评估这些肽是否具有预测HIV-1感染的能力 人已经制造了类似于单抗2G12和2F5的抗体。我们假设 在大多数HIV-1感染过程中都会产生中和抗体，尽管 在非常低的水平下，因此，“正确的”疫苗应该能诱导这些抗体 在大多数人身上。

DESCRIPTION: (Adapted from Applicant's Abstract) None of the vaccines in trials today elicit antibody (Abs) that neutralize a broad range of primary isolates of the type-1 human immunodeficiency virus (HIV-1). Three human Abs that neutralize a broad range of HIV-1 primary isolates have been cloned: MAbs bl2 and 2G12 and 2F5. Passive immunization with these MAbs produces sterilizing protection against IV and mucosal challenge of macaques with pathogenic SHIV strains. This supports the hypothesis that an active vaccine that stimulates the production of Abs similar or identical to MAbs bl2, 2F5 and 2G12 should provide effective prophylaxis against HIV- 1 infection. We propose to develop and optimize vaccine-lead peptides that would induce the production of neutralizing Abs having properties (and perhaps structures) similar to those of MAbs 2F5 and 2G12. We have already identified unique peptide ligands for both MAbs, and now propose to optimize them using a combination of phage display technology and synthetic peptides. The optimized peptides will be tested as immunogens in conjugate vaccines. With previous R21 funding, we developed B2.1, a homodimeric peptide that binds specifically and selectively to MAb bl2 (it is now in advanced stages of optimization), and have prepared conjugates and begun testing it as a vaccine. We have shown so far that the B2.1 peptide produces strong anti-peptide Ab titers when used as a conjugate vaccine in mice, and perhaps, weak cross-reactivity to gpl20 (this awaits further confirmatory testing). B2.1 also appears to identify bl2-like reactivities in the sera of some HIV-1 infected people. We plan similar work for the 2G12 and 2F5 leads; they are only in the very early stages of development. By means of functional and structural studies, we will probe the basis of the reactivity of the MAbs with their corresponding peptides in order to engineer high-affinity peptide ligands. We will test those peptides for their ability to elicit HIV-1-cross-reaetive Abs following two immunization strategies in mice, XenoMouse animals and macaques; and will then test the immune sera for the presence of HIV-1-binding Abs and for neutralizing activity. We will also assess the peptides for their ability to predict whether a HIV-1-infected person has made Abs that are similar to MAbs 2G12 and 2F5. We hypothesize that neutralizing Abs are produced throughout most of the HIV- 1 infection, albeit at very low levels, and thus, that "the right" vaccine should elicit these Abs in most people.