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Early events in the pathogenesis of Marek - OD0713

Marek`s disease (MD) is a naturally-occuring neoplasia and immunosuppresive disease of the domestic chicken. The UK poultry industry faces the re-emergence of this disease as a serious economic, health and welfare problem for the intensive use of MD vaccines has led to the emergence of increasingly virulent pathotypes of MD virus (MDV) in many countries, including the UK. Current vaccine strains obtained by attenuating pathogenic MDV themselves border on being harmful in susceptible birds and there is a need to identify critical stages in MDV infection where novel vaccines or other intervention strategies can be targetted.

This programme will investigate the very early stages of MDV infection by the natural route through the respiratory tract, a subject that has recieved little attention during the last 30 years. The project is to identify early events in MDV infection that are pivotal in determining the viral load and subsequent course of MD. The aims are to: (1) identify the site(s) within the respiratory tract where cell-free MDV enters the chicken, (2) identify the cells that take-up MDV and transport it to the lymphoid tissues, (3) determine the specific sites and extent of early amplification in different leukocyte populations in resistant and susceptible chickens and (4) identify genes that regulate these events.

The objectives are to provide the basis for improving resistance to MD in commercial poultry by (1) developig new vaccine strategies (2) enhancing immune responses to the early events in MDV infection, (3) devising novel pharmaceutical-based intervention strategies and/or (4) identifying host genes that reduce the viral load during the acute (cytolytic) phase of MD.

This work addressess key objectives outlined by MAFF by (1) developing novel intervention strategies for the control of an economically important disease (2) improving the health, welfare and immunity of commercial poultry by improving the effectiveness of vaccination and/or (3) identifying genetic mechansisms that can be harnessed for selective breeding programmes. The outcome will be increased competitiveness of the poultry industry in the UK through a reduction in economic losses caused morbidity and mortality from MD. It should lead to improved health and welfare of poultry as well as increased product quality for the cunsumer. It will also maintain and strengthen the base of expertise for work on an important oncogenic virus which is in a position to jump species barriers through the food chain.
1) Determination of the uptake of cell-free MDV
2) Effect of altering the numbers of cells carrying MDV to the lymphoid tissues.
3) The importance of B lymphocytes in early viral amplification.
4) The effect of MDV infection on different leukocyte populations
5) Factors influencing MDV replication in the lymphoid tissues
Project Documents
• Final Report : Early events in the pathogenesis of Marek   (594k)
Time-Scale and Cost
From: 2000

To: 2003

Cost: £384,453
Contractor / Funded Organisations
Institute for Animal Health (BBSRC)
Animal Diseases              
Animal Health              
Plants and Animals              
Fields of Study
Animal Health