Commensal/ Food bacteria-based DNA vaccine and DNA vaccine-delivery system.
The present invention is a medical invention related to a new HIV (Human Immunodeficiency Virus – the causative agent for AIDS) vaccine-delivery system. A majority of the HIV infections occur at mucosal sites either by sexual contact or by breastfeeding. Therefore, blocking HIV entry at the mucosal site is critical to prevent infection. Various bacterial vectors are used to deliver HIV vaccines, including Listeria, Salmonella, Shigella, and Yersinia. However, they are unsuitable because these potential lethal pathogens require extensive attenuations rendering them less effective. Secondly, none of these bacteria colonize the human oral cavity or the vagina, the ports of HIV entry. The present inventors have constructed novel HIV DNA mucosal vaccines based on commensal (Streptococcus gordonii) and food (Lactococcus lactis) bacteria. These bacteria will release DNA vaccine plasmids inside the host immune cells in the orogastrointestinal and vaginal tracts, and may induce strong immune responses in animals. The system of the present invention can deliver live vaccines safely as a food. It can deliver many types of DNA vaccines to the mucosal surfaces for disease prevention and/or treatment.
