Southeast Poultry Research Laboratory, Agricultural Research Services, U.S. Department of Agriculture, Athens, Georgia, USA.
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, USA.
J Virol. 2014 Aug;88(15):8397-406. doi: 10.1128/JVI.01321-14. Epub 2014 May 14.
Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is controlled mainly through biosecurity and vaccination with live attenuated strains of ILTV and vectored vaccines based on turkey herpesvirus (HVT) and fowlpox virus (FPV). The current live attenuated vaccines (chicken embryo origin [CEO] and tissue culture origin [TCO]), although effective, can regain virulence, whereas HVT- and FPV-vectored ILTV vaccines are less efficacious than live attenuated vaccines. Therefore, there is a pressing need to develop safer and more efficacious ILTV vaccines. In the present study, we generated Newcastle disease virus (NDV) recombinants, based on the LaSota vaccine strain, expressing glycoproteins B (gB) and D (gD) of ILTV using reverse genetics technology. These recombinant viruses, rLS/ILTV-gB and rLS/ILTV-gD, were slightly attenuated in vivo yet retained growth dynamics, stability, and virus titers in vitro that were similar to those of the parental LaSota virus. Expression of ILTV gB and gD proteins in the recombinant virus-infected cells was detected by immunofluorescence assay. Vaccination of specific-pathogen-free chickens with these recombinant viruses conferred significant protection against virulent ILTV and velogenic NDV challenges. Immunization of commercial broilers with rLS/ILTV-gB provided a level of protection against clinical disease similar to that provided by the live attenuated commercial vaccines, with no decrease in body weight gains. The results of the study suggested that the rLS/ILTV-gB and -gD viruses are safe, stable, and effective bivalent vaccines that can be mass administered via aerosol or drinking water to large chicken populations.
This paper describes the development and evaluation of novel bivalent vaccines against chicken infectious laryngotracheitis (ILT) and Newcastle disease (ND), two of the most economically important infectious diseases of poultry. The current commercial ILT vaccines are either not safe or less effective. Therefore, there is a pressing need to develop safer and more efficacious ILT vaccines. In the present study, we generated Newcastle disease virus (NDV) recombinants expressing glycoproteins B (gB) and D (gD) of infectious laryngotracheitis virus (ILTV) using reverse genetics technology. These recombinant viruses were safe, stable, and immunogenic and replicated efficiently in birds. Vaccination of chickens with these recombinant viruses conferred complete protection against ILTV and NDV challenge. These novel bivalent vaccines can be mass administered via aerosol or drinking water to large chicken populations at low cost, which will have a direct impact on poultry health, fitness, and performance.
本研究描述了针对鸡传染性喉气管炎（ILT）和新城疫（ND）的新型二价疫苗的开发和评估，这两种疾病是家禽最重要的两种经济上重要的传染病。目前的商用传染性喉气管炎疫苗要么不安全，要么效果不佳。因此，迫切需要开发更安全、更有效的传染性喉气管炎疫苗。在本研究中，我们使用反向遗传学技术生成了表达传染性喉气管炎病毒（ILTV）糖蛋白 B（gB）和 D（gD）的新城疫病毒（NDV）重组体。这些重组病毒安全、稳定、具有免疫原性，并且在鸟类中高效复制。用这些重组病毒对鸡进行免疫接种可完全预防 ILTV 和 NDV 攻毒。这些新型二价疫苗可通过气溶胶或饮水以低成本大规模施用于大型鸡群，这将对家禽的健康、适应性和性能产生直接影响。
