Pre-clinical Vaccine Development for Respiratory Viruses

人类副粘病毒和肺炎病毒是广泛传播的病原体，造成相当大的疾病负担。1-4型副流感病毒（PIV1-4）是高度传染性的人类病原体，其中PIV3最常导致新生儿、老年人和免疫功能低下个体的严重呼吸道疾病。基于工程PIV3 F预融合稳定三聚体的低温电镜结构，我们在四种PIV融合(F)糖蛋白中分别设计了不同于之前发表的修饰的额外突变，以进一步稳定其亚稳态预融合状态。候选疫苗能够引起小鼠PIV类型特异性反应，与其他PIV很少交叉中和。我们评估了候选疫苗在非人灵长类动物（NHPs）中的中和反应。我们将类似的概念和设计应用于hMPV F蛋白。在过去的一年里，我们设计了各种突变来进一步稳定PIV F预融合三聚体和hMPV预融合三聚体。此外，我们设计了修饰后的三聚体作为疫苗免疫原在不同纳米颗粒表面的表达。目前，我们正在尝试对修饰后的三聚体进行抗原性评价，并选择了最稳定的三聚体用于小鼠和NHP动物免疫原性研究。动物实验正在积极进行。

Human paramyxoviruses and pneumoviruses are widespread pathogens, cause considerable disease burden. Parainfluenza virus types 1-4 (PIV1-4) are highly infectious human pathogens, of which PIV3 is most commonly responsible for severe respiratory illness in newborns, elderly, and immunocompromised individuals. Based on a cryoelectron microscopy structure of an engineered PIV3 F prefusion-stabilized trimer, we engineered in additional mutations different from our previous published modifications in each of the four PIV fusion (F) glycoproteins to further stabilize their metastable prefusion states. The vaccine candidates were able to elicit murine PIV type-specific response, with little cross-neutralization of other PIVs. We evaluated the neutralization responses of the vaccine candidates in nonhuman primates (NHPs). We applied similar concept and designs to hMPV F proteins. In the past year, we designed various mutations to further stabilize the PIV F prefusion trimers and hMPV prefusion trimers. In addition, we designed expression the modified trimers on the surface of different nanoparticles as vaccine immunogens. We are now trying to evaluate the antigenicity of the modified trimers and we selected the most stable ones for mice and NHP animal immunogenicity study. The animal studies are actively going on.