A dual vaccine strategy against filovirus infection

描述(申请人提供)：该项目专注于开发一种有效的丝状病毒感染疫苗，丝状病毒感染是高致命性出血热的病原体，可通过人与人之间的接触传播，从而构成疫情暴发的高威胁。我们研究了针对病毒感染的VLP疫苗的开发，结果表明，利用重组杆状病毒表达系统在昆虫细胞中生产的EBOV VLP产量高，具有DC刺激活性，并能诱导强烈的抗体反应，中和EBOV GP介导的病毒感染，表明这种VLP可能是安全有效的疫苗，诱导对EBOV感染的保护性免疫。我们还发现，与单独使用DNA和VLP疫苗(DNA/VLP)相比，DNA和VLP疫苗混合免疫可诱导更高水平的抗体和细胞免疫反应。我们推测，新型DNA/VLP疫苗将引起对丝病毒感染的强大细胞和抗体反应，而采用新的疫苗递送技术将进一步增强对这种反应的诱导，目的是获得一种能够快速和持久地预防丝状病毒感染的疫苗策略。具体目的1.提高DNA疫苗和VLP疫苗的免疫原性，以诱导对泛丝病毒感染更有效和持久的保护性免疫。我们将探索不同的策略来修饰丝状病毒DNA和VLP疫苗，以提高它们诱导抗体和T细胞反应的免疫原性以及产量，并将确定有助于和关键的免疫反应，以实现对丝病毒感染的长期保护。具体目的2.评价微针技术在丝状病毒疫苗接种中的应用。我们将开发将丝状病毒DNA和VLP疫苗封装成可生物吸收的MN的技术，并研究微囊化疫苗的生物学特性、稳定性和免疫原性，并研究不同的几何设计和化学配方，以进一步改进MN疫苗的输送技术，实现更高效、更可重复的疫苗封装，提高疫苗的稳定性。具体目的3.比较不同疫苗接种方法的保护效果，确定保护丝病毒感染的免疫相关因素。我们将比较使用传统肌肉注射和新的MN疫苗递送技术的不同疫苗配方所诱导的免疫反应，并评估它们在小型实验动物模型和非人类灵长类动物中对抗致命丝状病毒攻击的保护效果，并将确定对实现对丝状病毒感染的长期保护至关重要的免疫反应的相关性。这些结果将为选择最有效的GMP生产和人体试验候选疫苗策略奠定基础。这一疫苗策略的成功开发也可以很容易地应用于针对其他病毒性出血热的疫苗，这些病毒出血热仍然缺乏有效的疫苗。

DESCRIPTION (provided by applicant): This project focuses on development of an effective vaccine for filovirus infection, which is an etiologic agent of highly lethal hemorrhagic fever and can be transmitted via person-to-person contact, thus posing a high threat of an epidemic outbreak. We have studied the development of VLP vaccines against virus infection, and have shown that EBOV VLPs produced in insect cells using the recombinant baculovirus expression system, which gives high VLP production yield, exhibit DC-stimulating activity and induce strong antibody responses that neutralize EBOV GP mediated virus infection, indicating that such VLPs could be safe and effective vaccines to induce protective immunity against EBOV infection. We also found that immunization with a mixture of DNA and VLP vaccines (DNA/VLP) induced higher levels of both antibody and cellular immune responses in comparison to immunization with either alone. We hypothesize that the novel DNA/VLP vaccine will elicit strong cellular and antibody responses against filovirus infection and that the employment of a new vaccine delivery technology will further augment induction of such responses, with the aim to obtain a vaccine strategy that can confer rapid and long lasting protection against filovirus infection. Specific Aim 1. To improve the immunogenicity of DNA and VLP vaccines for eliciting more potent and durable protective immunity against pan-filovirus infection. We will explore different strategies to modify filovirus DNA and VLP vaccines to enhance their immunogenicity for inducing both antibody and T cell responses as well as their production yield and will determine the immune responses that contribute to and are critical for achieving long lasting protection against filovirus infection. Specific Aim 2. To evaluate the microneedle (MN) technology for filovirus vaccine delivery. We will develop the technology to encapsulate filovirus DNA and VLP vaccines into bio-absorbable MNs and investigate the biological property, stability, and immunogenicity of encapsulated vaccines and investigate different geometrical designs and chemical formulations to further improve the MN vaccine delivery technology for achieving more efficient and reproducible vaccine encapsulation, and improved vaccine stability. Specific Aim 3. To compare the protective efficacy of different vaccine approaches and determine the immune correlates for protection against filovirus infection. We will compare immune responses induced by different vaccine formulations using both conventional intramuscular injection as well as the novel MN vaccine delivery technology and evaluate their protective efficacy against lethal filovirus challenge in small laboratory animal models as well as non-human primates and will determine the correlates of immune responses that are important for achieving long lasting protection against filovirus infection. The results will set the foundation for selection of the most effective candidate vaccine strategy for GMP production and human trials. The successful development of this vaccine strategy may also be readily applied to vaccines against other viral hemorrhagic fevers which still lack effective vaccines.