NOVEL VLP VACCINES FOR PANDEMIC INFLUENZA VIRUS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 本项目的目标是研究DNA和VLP疫苗混合物在引发针对流感病毒感染的保护性免疫应答中的潜在有效性。 高致病性禽流感病毒的反复爆发构成了致命疾病大流行的威胁，并使开发安全有效的疫苗成为优先事项。 流感病毒样颗粒（VLP）已被认为是一种有前途的疫苗方法。然而，VLP诱导的免疫应答及其在诱导记忆免疫应答和交叉保护性免疫中的作用尚未研究。在这项研究中，我们开发了含有流感病毒A/PR 8/34（H1N1）血凝素（HA）和基质（M1）蛋白的VLP，并研究了它们的免疫原性，长期交叉保护效力以及对小鼠肺促炎细胞因子的影响。 用含有HA的VLP鼻内免疫诱导高血清和粘膜抗体滴度，以及针对PR 8以及A/WSN/33（H1N1）病毒的中和活性。 用含有HA的VLP免疫的小鼠显示出很少或没有促炎性肺细胞因子，并且即使在免疫后5个月也被保护免于小鼠适应的PR 8或WSN病毒的致命攻击。流感病毒样颗粒诱导粘膜IgG和细胞免疫反应，这些反应在病毒攻击后迅速重新激活。 免疫小鼠骨髓中检测到长寿命抗体分泌细胞。免疫血清在鼻内给药时能够提供100%的保护，免受PR 8或WSN的致命攻击，这进一步证明了抗HA抗体主要负责预防感染。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to investigate the potential effectiveness of a mixture of DNA and VLP vaccines in eliciting protective immune responses against influenza virus infection. Recurrent outbreaks of highly pathogenic avian influenza virus pose the threat of pandemic spread of lethal disease and make it a priority to develop safe and effective vaccines. Influenza virus-like particles (VLPs) have been suggested to be a promising vaccine approach. However, VLP-induced immune responses, and their roles in inducing memory immune responses and cross-protective immunity have not been investigated. In this study, we developed VLPs containing influenza A/PR8/34 (H1N1) hemagglutinin (HA) and matrix (M1) proteins, and investigated their immunogenicity, long-term cross-protective efficacy, and effects on lung pro-inflammatory cytokines in mice. Intranasal immunization with VLPs containing HA induced high serum and mucosal antibody titers, and neutralizing activity against PR8 as well as A/WSN/33 (H1N1) viruses. Mice immunized with VLPs containing HA showed little or no pro-inflammatory lung cytokines and were protected from a lethal challenge with mouse-adapted PR8 or WSN viruses even 5 months post-immunization. Influenza VLPs induced mucosal IgG and cellular immune responses, which were reactivated rapidly upon virus challenge. Long-lived antibody secreting cells were detected in the bone marrow of immunized mice. Immune sera when administered intranasally were able to confer 100% protection from a lethal challenge with PR8 or WSN, which provides further evidence that anti-HA antibodies are primarily responsible for preventing infection.