First mucosal prion vaccine
The NYU study is also the first to use a mucosal prion vaccine, given by mouth rather than through the skin, which localizes the initial immune response to the gut and mainly stimulates an antibody response, says Dr. Wisniewski. "By giving our vaccine orally, we're stimulating an immune response mainly in the digestive tract," he explains. "Thus, harmful prions in contaminated food will be destroyed in the gut and will not reach other organs in the body." Because the research was conducted in normal mice, the NYU researchers say it will be easier to apply in animals in the wild, which are at risk for developing prion disease.
Prion disease is contracted when an animal eats the body parts of other animals contaminated with prions. What makes these infectious particles unusual is that they are proteins that have the same amino acid composition as equivalent proteins occurring naturally in the body. But the prions turn deadly by changing shape. These "misfolded" proteins tend to aggregate in toxic, cell-killing clumps. As an infection takes hold, prion proteins invade brain tissue and force normal proteins to adopt their configuration. In time, the diseased animal develops dementia, loses control of its limbs, and eventually dies.
There are no treatments for prion-related diseases, and prions can easily infect the body because they do not elicit any immune response.
To create a vaccine that could rally the immune system of mice, the NYU researchers designed a vaccine in which scrapie prions were attached to a genetically modified strain of Salmonella. This bacterium is also used in several animal vaccines and in human vaccines for cholera and ty
Source:NYU Medical Center