POLIOVIRUS REPLICONS FOR HIV/SIV VACCINES

因为流行病学研究表明，80%以上的感染 感染艾滋病毒的人是在粘膜表面获得的，一种安全有效的疫苗 必须具有刺激粘膜和全身免疫的特性 回应。感染脊髓灰质炎病毒会刺激两者 体液和细胞介导的系统免疫系统的组成部分。 在上一次资助期间，我们研发了重组脊髓灰质炎病毒。 基因组，称为复制子，其中衣壳基因已被取代 携带HIV/SIV基因。一种提供衣壳蛋白的互补系统 已经开发了反式病毒来封装复制子。小鼠的免疫或 具有囊化复制子的灵长类动物可产生针对 靶向HIV/SIV蛋白。提议的实验的目标是 进一步优化HIV蛋白的表达，增强 复制子的免疫原性。具体目标是： 特异性目标1：优化脊髓灰质炎病毒HIV包膜蛋白的表达 复制人。为此，我们将修改HIV env基因以编码不同的 分泌易位(信号序列)。复制图标的修改 将制作载体以增加HIV env的表达。 特定目的2：增强包埋复制子的感染性。至 增强与目标细胞的互动，将测试复制子 含有与衣壳结合的霍乱毒素B亚单位(CTB)，或 修饰衣壳以表达细胞表面整合素结合基序 (RGD)。根据之前的研究，我们将证实复制体 制备成脂质体-耳蜗剂可绕过受体介导 感染。我们将确定修改后的复制件是否显示增强 外源蛋白在原代培养中的感染和表达 树突状细胞的巨噬细胞。 具体目标3：测试复制子配方的诱导能力 免疫反应。目标1和目标2中描述的修改后的复制品将是 在含有该受体的转基因小鼠中进行免疫原性测试 脊髓灰质炎病毒。编码细胞因子的复制子将被评估为增强 免疫原性。优化配方将在#年进行评估 灵长类动物与富尔茨博士(项目3)和莱特文博士(项目4)。 在上一个资助期内进行的研究确立了 复制子作为疫苗载体的可行性。这些实验 旨在优化HIV/SIV蛋白的表达并增强 免疫原性对于疫苗的完整评价至关重要。 未来临床试验所需的策略。

Since epidemiological studies indicate that more than 80% of infections with HIV are acquired at mucosal surfaces, a safe and effective vaccine must have the properties to stimulate both the mucosal and systemic immune responses. Infection with poliovirus results in the stimulation of both humoral and cell mediated components of the systemic immune systems. During the last funding period, we developed recombinant poliovirus genomes, termed replicons, in which the capsid gene has been substituted with HIV/SIV genes. A complementation system to provide capsid proteins in trans has been developed to encapsidate replicons. Immunization of mice or primates with encapsidated replicons results in an immune response against the target HIV/SIV protein. The goal of the proposed experiments is to further optimize the expression of HIV proteins, and enhance the immunogenicity of the replicons. The Specific Aims are: Specific Aim 1: To optimize the expression of HIV envelope from poliovirus replicons. To do this, we will modify the HIV Env gene to encode different secretory translocation (signal sequences). Modifications of the replicon vector will be made to allow increased expression of HIV Env. Specific Aim 2: To enhance infectivity of encapsidated replicons. To enhance interactions with the target cell, replicons will be tested that contain the B subunit of cholera toxin (CTB) conjugated to the capsid, or the capsid modified to express a cell surface integrin binding motif (RGD). Based on previous studies, we will confirm that replicons formulated into liposome-cochleates can circumvent receptor mediated infection. We will determine if the modified replicons show enhanced infection and expression of foreign proteins in primary cultures of macrophages of dendritic cells. Specific Aim 3: To test replicon formulations for the ability to induce immune responses. The modified replicons described in Aims 1 and 2 will be tested for immunogenicity in transgenic mice that contain the receptor poliovirus. Replicons encoding cytokines will be evaluated for enhancement of the immunogenicity. The optimized formulation will be evaluated in primates with Drs. Fultz (Project 3) and Letvin (Project 4). Studies conducted during the last funding period have established the feasibility of using replicons as vaccine vectors. The experiments designed to optimize the expression of HIV/SIV proteins and enhance immunogenicity are essential for the complete evaluation of vaccine strategies required for future clinical trials.