Salmonella vaccine research has reached a remarkable milestone. Scientists at UC Davis, in collaboration with researchers from the University of Melbourne and the University of Connecticut, have published a landmark study in the Proceedings of the National Academy of Sciences identifying the specific cells responsible for optimal protection against Salmonella infection.<\/p>\n
For decades, immunology research focused almost exclusively on antibody and circulating T cell responses. This new Salmonella vaccine research shifts that focus entirely. Professor Stephen McSorley, interim director of the Center for Comparative Medicine at UC Davis, led the team that discovered non-circulating memory T cells, also known as tissue resident memory cells, are the critical component for protection against Salmonella infection.<\/p>\n
These cells never move through the body the way circulating T cells do. They remain fixed in tissues and, as this Salmonella vaccine research confirms, they are far more effective at preventing reinfection than previously understood cell populations.<\/p>\n
The research team transferred both circulating and non-circulating memory T cells from previously vaccinated mice into unvaccinated mice. Using fluorescent markers, they tracked which cell type provided protection against Salmonella infection. The results were clear: vaccine mediated protection requires a non-circulating population of liver memory T cells that do not travel through the rest of the body.<\/p>\n
This unexpected finding means that generating these specific liver memory T cells will form the basis of future Salmonella vaccine research and development efforts worldwide.<\/p>\n
Non-typhoidal Salmonellosis has emerged as a serious threat in sub-Saharan Africa over the past decade, primarily affecting young children, elderly individuals, and those with HIV. In resource poor communities across Asia and Africa, the disease causes systemic infection and carries a fatality rate of 20 to 25 percent without medical care.<\/p>\n
Two Salmonella vaccines currently exist, but neither is practical for use in the most affected regions and each protects only about 50 percent of immunized individuals. This gap is precisely what drives the UC Davis team forward.<\/p>\n