Investigation of the Molecular Basis for ND Virulence to Allow Improved Assessment of Risk Factors for Infection

<p>Newcastle disease (ND), caused by virulent strains of avian paramyxovirus type 1 is regarded as one of the most important avian diseases throughout the world.</p>

<p>This study offers the opportunity to address the variable threat of introduction and spread of NDV to multiple poultry species to ensure the UK remains free from this exotic disease. Biological data generated will provide information for risk based analysis to refine cost effective surveillance which will potentially result in improved threat detection. As a result, this will help to ensure a sustainable UK poultry industry and that food production as well as export opportunities are not compromised. Essentially, the funding of this work ensures the strong NDV research programme and specialisation remains, effectively underpinning and maintaining our capability to provide disease emergency response and expertise as the UK national laboratory.</p>

<p>The mechanisms responsible for both the maintenance of virulent Newcastle disease viruses (NDV) in bird populations and emergence of virulence are not completely understood. The aim of this study is to explore factors that lead to the highly variable disease presentations observed in different species infected with NDV and ascertain if these factors contribute to the maintenance or emergence of virulence. Several reports suggest that the NDV V protein, a component of the NDV genome that is involved in blocking the host immune response, has a role in virus virulence and host specificity. It has also been demonstrated that the V protein is effective in blocking the immune response in a host specific manner and that mutated virus where the V protein was removed showed attenuated virulence for chickens. The possibility that this is one of the factors involved in variable disease presentation observed in different poultry species will be explored.</p>

<p>In the proposed study, the hypothesis that the NDV V protein has a role in virulence and host restriction will be investigated. The genetic variability of the NDV genome will be established and the biological properties of selected viruses showing genetic variations in the V protein will be evaluated using a number of in vitro and in vivo approaches. The specific properties of the V gene variants will be evaluated in both wild type and variant or modified viruses. </p>