Work Package 2
Contribution of gamma/delta T cells to long-term immunity against Salmonella infection in chickens
Salmonella Enteritidis was the most frequently reported pathogen for foodborne outbreaks in the European Union in 2023. Salmonellosis in humans is mostly caused by the consumption of contaminated poultry products such as eggs, egg products and chicken meat. The economic impact of Salmonella infections in the poultry industry, includes direct losses due to a decreased productivity and increased mortality. Vaccination is one of the most important measures to control Salmonella infection and spread in the poultry industry, but with varying degrees of success. In order to further
reduce the Salmonella burden in poultry flocks, more detailed knowledge of the immunological defense mechanisms in chickens is required. For Salmonella infection in laying hens, it has already been postulated that certain subpopulations of γδ T cells could be decisive for the outcome of the disease.
In the first ImmunoChick funding period, we showed that γδ T cells indeed play a role in the immune response against Salmonella infections in laying hens. The γδ T cell knockout chickens showed a stronger Salmonella invasion in liver and cecum than wild-type chickens. We also showed that the absence of γδ T cells in the knockout chickens can be compensated by other immune cells including αβ T cells. However, the role and function of γδ T cell subsets or their compensatory counterparts in maintaining sustained immune protection against Salmonella remains unknown.
In the second ImmunoChick funding period, we want to continue our work and investigate whether γδ T cells can contribute to the development of immunological memory and fulfill specific functions to protect chickens long-term against Salmonella infections. Therefore, we will use Salmonella vaccinated and infected γδ T cell knockout and wild type chickens to analyse the potential immunological memory functions of γδ T and αβ T cells. To this end, we will measure the recall functions such as proliferation, migration and cytotoxicity of γδ and αβ T cells in vitro. In vivo, we will investigate the development of immunological γδ and αβ T memory cells. In addition, we will focus our research on the role of γδ T cell subsets in maintaining the integrity of the intestinal barrier in chickens. These experiments will reveal the location and distribution of γδ and αβ T cell subsets and different barrier-specific proteins in specific areas of the intestine of Salmonella vaccinated, infected and re-infected γδ T cell knockout and wild-type chickens.
The proposed study is only possible through collaboration with ImmunoChick members and will provide important insights into both Salmonella infection and the immune system of chickens.
Principal investigator:
PhD-student:
tba