January 8, 2018
Newly discovered chicken immune cell increases susceptibility to Marek's disease
A new type of immune cell in chickens involved in the development of Marek's disease has been identified by scientists at The Pirbright Institute in Surrey, England.
Marek's disease virus (MDV) is highly contagious and causes a deadly cancer of the lymph nodes (lymphoma) and immunosuppression in poultry, making birds susceptible to secondary infections. MDV is a major threat to the poultry industry, which leads to losses estimated at up to $2 billion worldwide.
The research, published in PLOS Pathogens medical journal, revealed that infection with Marek's disease virus increases the number of new immune cells, called suppressor lymphocytes, which suppress the chicken immune response.
The study also showed that higher numbers of suppressor lymphocytes increased the susceptibility of chickens to lymphoma formation.
"Some viruses exploit host immune cells for their own purpose to evade normal host defences. We found that MDV can modulate immune responses by activating suppressor lymphocytes, contributing to immunosuppression and lymphoma formation", said Dr Shahriar Behboudi, head of the Avian Immunology group at Pirbright, a world leading centre of excellence in research and surveillance of virus diseases of farm animals and viruses that spread from animals to humans.
The scientists also noted that lymphoma cells have similar characteristics to suppressor lymphocytes, meaning they too can suppress immune responses.
Combined, these findings identify new pathways that are involved in the development of the disease, which can help identify chicken lines that are more resistant to MDV, the study said.