Project 1: Development of Nucleoside-Modified mRNAs Encoding Sequential HIV-1 Envelopes for Initiation of V3-glycan Neutralizing Antibody Lineages

项目1：开发核苷修饰的编码HIV-1包膜序列的mRNA， V3-聚糖中和抗体谱系的起始 HIV-1疫苗开发的一个主要目标是诱导广泛中和抗体（bnAb）。这个IPCAVD 一个研究小组拥有可以触发bnAb B细胞谱系的未突变共同祖先（UCA）的免疫原，这是一个关键 艾滋病疫苗的方法。一种称为EnvSeq-3的这样的连续Env免疫原衍生自 CH 848 HIV-1感染个体的研究，该个体制备了DH 270 HIV V3聚糖靶向bnAb。我们 假设使用与DH 270 B细胞谱系UCA结合的引发免疫原， 通过顺序修饰的mRNA gp 160或gp 140三聚体为基础的免疫原将导致启动 人中的V3-聚糖bnAb B细胞谱系。 ·具体目标1.设计并配制编码两种核苷修饰的连续mRNA， gp 160或可溶性嵌合的、稳定的三聚体，其结合DH 270的中间抗体 B细胞谱系。核苷修饰的mRNA编码免疫后的前2个三聚体谱系免疫原。 将使用已建立的技术优化V3-糖肽以进行高水平表达。 ·具体目标2。确定合成UCA结合糖肽是否与GLA/SE结合 佐剂将引发DH 270 UCA B细胞，用于用DH 270中编码Env三聚体的mRNA加强 UCA VH和VL敲入小鼠。将分析糖肽和mRNA免疫原，包括 组合以证实在DH 270 UCA VH + VL敲入（KI）小鼠中它们对Tfh细胞的诱导， 选择靶向V3-聚糖bnAb位点的抗体。两种选择的mRNA将被产生 CGMP项目2。 ·具体目标3。在远交恒河猴中测试顺序免疫原以优化 免疫方案用于第5年的I期临床试验。 我们相信，编码V3-聚糖谱系免疫原的修饰的mRNA-LNP将产生有效的CD 4 + Tfh 和抗体应答，并将在bnAb KI小鼠和人类中引发V3-聚糖bnAb谱系。这 该项目将使用核苷修饰mRNA形式的有前途的顺序免疫原设计， 克服bnAb开发的障碍。如果成功，核苷修饰的mRNA的使用将改变 HIV-1疫苗研发。

Project 1: Development of Nucleoside-Modified mRNAs Encoding Sequential HIV-1 Envelopes for Initiation of V3-glycan Neutralizing Antibody Lineages A major goal of HIV-1 vaccine development is to induce broadly neutralizing antibodies (bnAbs). This IPCAVD team has immunogens that can trigger unmutated common ancestors (UCAs) of bnAb B cell lineages, a key approach for an HIV vaccine. One such sequential Env immunogen termed, EnvSeq-3, is derived from the study of the CH848 HIV-1-infected individual who made the DH270 HIV V3-glycan-targeted bnAb. We hypothesize that use of priming immunogens that bind to the UCA of the DH270 B cell lineage followed by sequential modified mRNA gp160 or gp140 trimer-based immunogens will result in the initiation of V3-glycan bnAb B cell lineages in humans. • Specific Aim 1. Design and formulate sequential nucleoside-modified mRNAs encoding two gp160s or soluble chimeric, stabilized trimers that bind to intermediate antibodies of the DH270 B cell lineage. Nucleoside-modified mRNA encoding the first 2 trimeric lineage immunogens after the V3-glycopeptide will be optimized for high level expression using established techniques. • Specific Aim 2. Determine if synthetic UCA-binding glycopeptides combined with GLA/SE adjuvant will prime DH270 UCA B cells for boosting with Env trimer-encoding mRNAs in DH270 UCA VH and VL knock-in mice. Glycopeptide and mRNA immunogens will be analyzed including combinations to confirm in DH270 UCA VH + VL knock-in (KI) mice their induction of Tfh cells and selection of antibodies that target the V3-glycan bnAb site. The two selected mRNAs will be produced CGMP in Project 2. • Specific Aim 3. Test sequential immunogens in outbred rhesus macaques to optimize immunization schemes for use in a phase I clinical trial in year 5. We believe that modified mRNA-LNPs encoding V3-glycan lineage immunogens will generate potent CD4+ Tfh and antibody responses, and will initiate V3-glycan bnAb lineages in bnAb KI mice and in humans. This project will use a promising sequential immunogen design in the form of nucleoside-modified mRNAs to overcome barriers to bnAb development. If successful, the use of nucleoside-modified mRNAs will transform HIV-1 vaccine development.