Schröer Diana, Veits Jutta, Keil Günther, Römer-Oberdörfer Angela, Weber Siegfried, Mettenleiter Thomas C
Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, D-17493 Greifswald-Insel Riems, Germany.
Avian Dis. 2011 Jun;55(2):201-11. doi: 10.1637/9539-092710-Reg.1.
A recombinant Newcastle disease virus (NDV) expressing H6 hemagglutinin (HA) of a low pathogenic avian influenza virus (LPAIV) was generated by reverse genetics (NDVH6). The H6 open reading frame was inserted as an additional transcription unit between the fusion and hemagglutinin-neuraminidase (HN) gene of lentogenic NDV clone 30. Expression of the foreign gene was demonstrated by northern blot, western blot, and indirect immunofluorescence analyses. The protective efficacy against Newcastle disease and avian influenza of subtype H6 was evaluated in 3-wk-old chickens and turkeys. A single vaccination protected specific-pathogen-free (SPF) chickens against a subsequent lethal NDV infection and prevented shedding of AIV after homologous H6 LPAIV infection. Furthermore, vaccinated and AIV-infected animals could be differentiated by detection of AIV nucleoprotein-specific antibodies. Three-week-old commercial turkeys, exhibiting NDV-specific maternal antibodies, were partially protected against a lethal NDV challenge infection. The mortality rate of NDVH6-immunized turkeys was reduced to 40% compared to 90% in unvaccinated birds. After H6 LPAIV infection, shedding in NDVH6-immunized turkeys was only marginally reduced compared to NDV-immunized control birds. We previously described HA-expressing NDV recombinants as potent bivalent vaccines against Newcastle disease and highly pathogenic avian influenza of subtype H5 or H7. The results presented here are in contrast to the high protective efficacy in SPF chickens, as a single vaccination with NDVH6 was insufficient in turkeys in the presence of maternal antibodies against NDV. Therefore, the vector virus has to be improved to overcome these limitations.
通过反向遗传学技术构建了一种表达低致病性禽流感病毒（LPAIV）H6血凝素（HA）的重组新城疫病毒（NDV）（NDVH6）。将H6开放阅读框作为一个额外的转录单元插入到弱毒NDV克隆30的融合基因和血凝素神经氨酸酶（HN）基因之间。通过Northern印迹、Western印迹和间接免疫荧光分析证实了外源基因的表达。在3周龄的鸡和火鸡中评估了其对新城疫和H6亚型禽流感的保护效力。单次接种疫苗可保护无特定病原体（SPF）鸡免受随后的致死性NDV感染，并在同源H6 LPAIV感染后防止禽流感病毒的排出。此外，通过检测禽流感病毒核蛋白特异性抗体可以区分接种疫苗和感染AIV的动物。具有NDV特异性母源抗体的3周龄商品火鸡对致死性NDV攻毒感染有部分保护作用。与未接种疫苗的火鸡90%的死亡率相比，接种NDVH6的火鸡死亡率降至40%。在H6 LPAIV感染后，与接种NDV的对照火鸡相比，接种NDVH6的火鸡病毒排出量仅略有减少。我们之前将表达HA的NDV重组体描述为针对新城疫和H5或H7亚型高致病性禽流感的有效二价疫苗。此处呈现的结果与在SPF鸡中的高保护效力形成对比，因为在存在针对NDV的母源抗体的情况下，单次接种NDVH6对火鸡是不够的。因此，必须改进载体病毒以克服这些局限性。
