NOVEL VLP VACCINES FOR PANDEMIC INFLUENZA VIRUS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 高致病性禽流感病毒的反复暴发构成了致命疾病大流行传播的威胁，使开发安全有效的疫苗成为当务之急。流感病毒样颗粒(VLP)已被认为是一种很有前途的疫苗方法。然而，VLP诱导的免疫反应及其在诱导记忆免疫反应和交叉保护免疫中的作用尚未被研究。在本研究中，我们研制了含有甲型H1N1流感病毒A/PR8/34(H1N1)血凝素(HA)和基质(M1)蛋白的VLP，并研究了它们的免疫原性、长期交叉保护效果以及对小鼠肺促炎症细胞因子的影响。含HA的VLP滴鼻免疫小鼠，可诱导高滴度的血清和粘膜抗体，并对PR8和A/WSN/33(H1N1)病毒具有中和活性。用含有HA的VLP免疫的小鼠显示很少或没有促炎细胞因子，即使在免疫后5个月，也能保护小鼠免受小鼠适应的PR8或WSN病毒的致命攻击。流感病毒VLP可诱导黏膜免疫应答和细胞免疫应答，并在病毒攻击后迅速被激活。免疫小鼠骨髓中可检测到长寿命的抗体分泌细胞。免疫血清滴鼻给药时，能够100%保护免受PR8或WSN的致命攻击，这提供了进一步的证据，表明抗HA抗体主要负责预防感染。综上所述，这些结果表明，非复制型流感VLP是开发安全有效的疫苗以控制致命流感病毒传播的一种有希望的战略。

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. 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. Taken together, these results indicate that non-replicating influenza VLPs represent a promising strategy for the development of a safe and effective vaccine to control the spread of lethal influenza viruses.