| Description |
Although the etiology of multiple sclerosis (MS) is unknown, several factors are believed to play a role in this disease: genetic components, immunologic elements, and environmental factors. The best explanation of the latter is viral infection. Chronic Theiler's murine encephalomyelitis virus (TMEV) infection in susceptible mice is an optimal model, mimicking several aspects of MS. DNA vaccination has been used experimentally to successfully protect animals against chronic viral infection. I created eukaryotic expression vectors with cDNA encoding the TMEV capsid proteins VP1, VP2, VP3, and VP4. I then vaccinated groups of SJL/J mice one, two, or three times with different plasmid construct. This was followed by live TMEV challenge to determine the protective effect, if any, that would be induced by DNA vaccination. It was demonstrated that vaccination of mice three times with DNA encoding VP2 lead to partial protection of mice from disease, demonstrated by a decrease in clinical symptoms and histopathology. Two vaccinations with cDNA encoding VP4 also lead to a decrease in clinical expression of disease. Additionally, mice vaccination one time with cDNA encoding VP1 experiences more serve disease and/or earlier onset clinically and histologically than control. Although there was no correlation between antibody titers and disease course, we could detect anti-capsid protein antibody in mice inoculated with only plasmid. These results indicate that DNA immunization may prevent chronic virus induced demyelinating disease, and in the future may be applied to illnesses such as MS. |
