Title: Immune responses of poultry to newcastle disease virus Authors
Submitted to: Developmental and Comparative Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 14, 2013
Publication Date: May 2, 2013
Citation: Kapczynski, D.R., Afonso, C.L., Miller, P.J. 2013. Immune responses of poultry to newcastle disease virus. Developmental and Comparative Immunology. 41. Available: http://dx.doi.org/10.1016/j.dci.2013.04.012 Interpretive Summary: Newcastle disease virus (NDV) is an economically important disease of poultry with outbreaks that can results in trade barriers. Although vaccination programs exist to control the disease, the use of dated vaccine isolates require constant testing to ensure potency. While antibodies provide protection from disease, the virus continues to evolve in chickens and other species. New technologies are allowing more in-depth analysis of the host immune response to NDV. Results of vaccine testing suggest that immunity conferred by older vaccines many not provide the best protection against NDV. The need for continued research on immunity to NDV is important in developing new vaccines and control strategies to protect poultry against this disease.
Technical Abstract: Newcastle disease (ND) remains a constant threat to poultry producers worldwide, in spite of the availability and global employment of ND vaccinations since the 1950s. Strains of Newcastle disease virus (NDV) belong to the order Mononegavirales, family Paramyxoviridae, and genus Avulavirus, are contained in one serotype and are also known as avian paramyxovirus serotype-1 (APMV-1). They are pleomorphic in shape and are single-stranded, non-segmented, negative sense RNA viruses. The virus has been reported to infect most all orders of birds and thus has a wide host range. Isolates are characterized by virulence in chickens and presence of basic amino acids at the fusion protein cleavage site. Low virulent NDV typically produce subclinical disease with some morbidity, whereas virulent isolates can result in rapid, high mortality of birds. Virulent NDV are listed pathogens that require immediate notification to the Office of International Epizootics and outbreaks typically result in trade embargos. Protection against NDV is through the use of vaccines generated with low virulent NDV strains. Immunity is derived from neutralizing antibodies formed against the viral hemagglutinin and fusion glycoproteins, which are responsible for attachment and spread of the virus. However, new techniques and technologies have also allowed for more in depth analysis of the innate and cell-mediated immunity of poultry to NDV. Gene profiling experiments have led to the discovery of novel host genes modulated immediately after infection. It has also been shown that differences in virus virulence alter host gene response patterns. Furthermore, the timing and contributions of cell mediated immune responses appear to decrease disease and transmission potential. In view of recent reports of vaccine failure from many countries on the ability of classical NDV vaccines to stop spread of disease, renewed interest in a more complete understanding of the global immune response of poultry to NDV will be critical to developing new control strategies and intervention programs for the future.