Progress in the Development of Lactococcus lactis as a Mucosal Vaccine Delivery Vehicle

Lactococcus lactis, a food-grade, non-pathogenic, non-invasive, non-colonizing and “generally regarded as safe” lactic acid bacteria, is widely used in food, medicine, and husbandry industry, and it is a potential and promising candidate as a mucosal vaccine delivery vehicle (MVDV). This review describes the latest research progress of L. lactis as an MVDV and its potential improvements. Firstly, the review introduces the advantages of using L. lactis as an MVDV, emphasizing the efficient controlled protein expression and protein-targeting systems developed for production of a desired antigen. Secondly, an extensive overview is given of the progress made in improving production yield and stability of the heterologous proteins expressed in L. lactis. Thirdly, an overview is provided of the efficiency of L. lactis as MVDV for mucosal immunization. Finally, the problems limiting the use of L. lactis as MVDV are introduced and probable methods to solve them are brought forward. _____________________________________________________________________________________________________________