PDF(Pubmed)
Abstract：
Influenza A viruses (IAV-S) belonging to the H1 subtype are endemic in swine worldwide. Antigenic drift and antigenic shift lead to a substantial antigenic diversity in circulating IAV-S strains. As a result, the most commonly used vaccines based on whole inactivated viruses (WIVs) provide low protection against divergent H1 strains due to the mismatch between the vaccine virus strain and the circulating one. Here, a consensus coding sequence of the full-length of HA from H1 subtype was generated in silico after alignment of the sequences from IAV-S isolates obtained from public databases and was delivered to pigs using the Orf virus (ORFV) vector platform. The immunogenicity and protective efficacy of the resulting ORFVΔ121conH1 recombinant virus were evaluated against divergent IAV-S strains in piglets. Virus shedding after intranasal/intratracheal challenge with two IAV-S strains was assessed by real-time RT-PCR and virus titration. Viral genome copies and infectious virus load were reduced in nasal secretions of immunized animals. Flow cytometry analysis showed that the frequency of T helper/memory cells, as well as cytotoxic T lymphocytes (CTLs), were significantly higher in the peripheral blood mononuclear cells (PBMCs) of the vaccinated groups compared to unvaccinated animals when they were challenged with a pandemic strain of IAV H1N1 (CA/09). Interestingly, the percentage of T cells was higher in the bronchoalveolar lavage of vaccinated animals in relation to unvaccinated animals in the groups challenged with a H1N1 from the gamma clade (OH/07). In summary, delivery of the consensus HA from the H1 IAV-S subtype by the parapoxvirus ORFV vector decreased shedding of infectious virus and viral load of IAV-S in nasal secretions and induced cellular protective immunity against divergent influenza viruses in swine.
摘要：
属于H1亚型的甲型流感病毒(IAV-S)在全世界猪中流行。抗原漂移和抗原转移导致循环IAV-S菌株中大量的抗原多样性。因此,最常用的基于完整灭活病毒(WIV)的疫苗由于疫苗病毒株与循环病毒株不匹配,对不同H1株的保护作用较低.这里,在对从公共数据库获得的IAV-S分离株的序列进行比对后,在计算机模拟中产生H1亚型HA全长的共有编码序列,并使用Orf病毒(ORFV)载体平台将其递送至猪.在仔猪中针对不同的IAV-S毒株评估了所得ORFVΔ121conH1重组病毒的免疫原性和保护效力。通过实时RT-PCR和病毒滴定评估用两种IAV-S毒株鼻内/气管内攻击后的病毒脱落。免疫动物的鼻分泌物中的病毒基因组拷贝和感染性病毒载量减少。流式细胞仪分析表明，T辅助/记忆细胞的频率，以及细胞毒性T淋巴细胞（CTL），与未接种疫苗的动物相比，接种疫苗组的外周血单核细胞（PBMC）在接受IAVH1N1大流行菌株（CA/09）的攻击时明显更高。有趣的是,在接受来自γ进化枝的H1N1病毒(OH/07)攻击的组中,与未接种疫苗的动物相比,接种疫苗的动物的支气管肺泡灌洗液中T细胞的百分比更高.总之,副痘病毒ORFV载体从H1IAV-S亚型递送共有HA减少了感染性病毒的脱落和鼻分泌物中IAV-S的病毒载量，并诱导了猪针对不同流感病毒的细胞保护性免疫。
