Durable HIV Vaccine Targeting Mucosal Epithelium

摘要 由实验性艾滋病毒/SIV疫苗产生的令人印象深刻的大量数据使人们实现了 这种保护很可能需要两级屏障，最初的屏障是在黏膜进入口岸，如果 被攻破的是第二套系统性防御系统。体液免疫和细胞免疫应答的能力 粘膜组织在病毒传播的初始阶段阻止或遏制复制可能会有深远的影响 对接种疫苗的宿主抵抗感染的能力的影响，即使在病毒进展超过 进入口岸，使全身反应有更多的时间来控制或根除传入的病原体。 我们假设，一种成功的疫苗有两个必要的特征：1)如果不是长期的，那么 用病毒抗原终生刺激免疫系统，以维持“警觉”的免疫反应；和2) HIV主要复制部位的靶向免疫反应。一种同时接种疫苗的方法 解决这两个问题将有可能实现扎实的、长期的积极保护。履行 为了满足这些要求，我们开发了一种独创的策略，成功地将疫苗输送到粘膜部位 在反复发作时提供抗原刺激，并引发保护性粘膜免疫反应。我们的 策略利用上皮干细胞作为永久但不表达病毒抗原的来源，而他们的 分化的后代沿着生殖周期表达并呈递抗原给当地的免疫系统。 使用单周期SIV(SIVsc)方法，与传统方法相比已被证明是安全的 在弱毒疫苗的基础上，我们已经克隆了SIVsc基因组，并将其控制在外膜蛋白启动子(pINV- SIVsc)，一个终末分化的角质形成细胞特异性启动子。当给药时，疫苗靶标和 从阴道组织中转导基底上皮干细胞。然后，这些细胞增殖并分化为成熟细胞 上皮细胞，通过启动子触发SIV抗原的表达，并导致直接和交叉启动。 对于这一项目，我们建议：1)确认并进一步改善 PINV-SIVsc疫苗在雌性猕猴中的应用；2)可视化和优化疫苗投放，并调查 保护基础的作用机制；以及，3)使用我们最优化的疫苗策略，证明 保护免受体内病毒感染和/或病毒复制，并确定保护或 异种SIV对反复低剂量阴道刺激的控制。

Abstract The impressive amount of data generated by experimental HIV/SIV vaccines has led to the realization that protection will most likely requires 2 levels of barriers, the initial one at the mucosal port of entry and if breached, a second set of systemic defenses. The capacity of humoral and cellular immune responses in mucosal tissues to block or contain replication at the initial stage of virus transmission may have a profound impact on the ability of a vaccinated host to resist infection, even in the case when virus progresses beyond the port of entry, allowing the systemic response more time to control or eradicate the incoming pathogen. We hypothesized that there are two necessary features for a successful vaccine: 1) A prolonged if not life-long stimulation of the immune system with viral antigens to maintain “alert” immune responses; and 2) a targeted immune response at the site of primary replication of HIV. A vaccine approach that simultaneously addresses these two issues would have the potential to achieve solid, long-term active protection. To fulfill these requirements, we have developed an original strategy to successfully deliver a vaccine to mucosal sites that provide antigen stimuli at recurrent intervals and elicit protective mucosal immune responses. Our strategy leverages epithelial stem cells as permanent but non-expressing source of viral antigen while their differentiated offspring express and present antigen to the local immune system, along the reproductive cycle. Using a single cycle SIV (SIVsc) approach, which has been shown to be safe compared to traditional attenuated vaccines, we have cloned the SIVsc genome under the control of the involucrin promoter (pINV- SIVsc), a terminally differentiated keratinocyte specific promoter. When administered, the vaccine targets and transduces basal epithelial stem cells from vaginal tissues. These then proliferate and differentiate into mature epithelial cells, triggering SIV antigen expression via the promoter and leading to both direct and cross priming. For this project, we propose: 1) To confirm and further improve the efficacy and safety profile of the pINV-SIVsc vaccine in female macaques; 2) To visualize and optimize vaccine delivery, and investigate the mechanisms of action underlying protection; and, 3) Using our best optimized vaccine strategy, demonstrate protection from virus acquisition and/or viral replication in vivo and determine the correlates of protection or control against repeated low-dose vaginal challenges with heterologous SIV.