Optimising genomic RNA RNA interactions for development of flexible influenza virus vector backbones for co vaccination

阿斯利康公司销售的流感减毒活疫苗(LAIV)名为FluMist/Fluenz，是英国儿童流感疫苗接种计划的支柱，每年作为鼻腔喷雾剂接种给所有2-12岁的儿童。与灭活疫苗不同，LAIV在产生显著的粘膜免疫方面是独一无二的(Barria等人，J Infect Dis，2013)，提供了预防病毒从上呼吸道传播到下呼吸道的可能性，从而产生了严重疾病的风险。在2013-14和2015-16流感季节，美国观察到流感病毒H1N1成分的疫苗效力较低，这是由于LAIV在人鼻上皮细胞中的复制减少(Hawksworth等人，Vaccine，2020)，而不是降低了HA抗原的稳定性(Parker等人，Vaccine 2019)。这种适应性降低的一个潜在因素是携带所有八个基因组片段的传染性病毒颗粒的产生减少。观察还表明，历史上的MDV基因组整合不同当代甲型流感病毒的HA和NA基因的能力可能会有所不同，导致LAIV毒株具有意想不到的复制差异。该项目旨在了解LAIV基因组片段是如何组装的，以便生物工程下一代LAIV，适合于所有季节性或大流行流感毒株的灵活载体，并联合接种SARS-CoV-2等病毒-我们还没有赋予这些病毒粘膜免疫力的疫苗。这种疫苗将是无价的，因为现有的疫苗在阻止传播方面基本上是无效的。该项目的目标是(1)绘制推动LAIV毒株组装的RNA：RNA相互作用图，(2)利用这一知识设计一个灵活的MDV骨干，使其能够有效地产生季节性或大流行性LAIV，(3)还可以作为与其他呼吸道病原体共同接种流感的灵活平台。

The Live Attenuated Influenza Vaccine (LAIV), marketed as FluMist/Fluenz by AstraZeneca forms the backbone of the United Kingdom's childhood influenza vaccination programme and is given as a nasal spray annually to all 2-12 year-olds. Unlike inactivated vaccines, LAIVs are unique in generating significant mucosal immunity (Barria et al., J Infect Dis, 2013), offering the possibility of pre-empting virus spread from the upper to lower respiratory tract and consequent risk of severe disease.In the 2013-14 and 2015-16 influenza seasons, low vaccine effectiveness was observed for the H1N1 component of FluMist in the USA, attributed to decreased LAIV replication in human nasal epithelial cells (Hawksworth et al., Vaccine, 2020), rather than decreased HA antigen stability (Parker et al., Vaccine 2019). One potential contributing factor to this reduced fitness was a decrease in the production of infectious virus particles carrying all eight genome segments. Observations also suggest that the ability of the historic MDV genome to incorporate HA and NA genes from different, contemporary influenza A viruses can vary, resulting in LAIV strains with unexpected replicative differences.This project aims to understand how the genome segments of LAIVs are assembled in order to bioengineer a next-generation of LAIVs suitable as flexible vectors for all seasonal or pandemic influenza strains and co-vaccination against viruses such as SARS-CoV-2 - to which we have no vaccine that confers mucosal immunity. Such a vaccine would be invaluable, since existing vaccines are largely ineffective at halting transmission.This project aims to (1) map RNA:RNA interactions that drive assembly of LAIV strains and (2) to use this knowledge to engineer a flexible MDV backbone enabling efficient generation of either seasonal or pandemic LAIV, that (3) can also act as a flexible platform for co-vaccination of influenza along with other respiratory pathogens.