30] Lactobacilli as vehicles for targeting antigens to mucosal tissues by surface exposition of foreign antigens

Abstract

Publisher Summary This chapter discusses lactobacilli as vehicles for targeting antigens to mucosal tissues by surfaces exposition for foreign antigens. Lactobacillus strains have a number of properties that make them attractive candidates as delivery vehicles for the presentation to the mucosa of compounds of pharmaceutical interest, in particular vaccines and immunomodulators. Lactobacilli have been used for centuries in fermentation and preservation of food and feed, and are considered GRAS (generally regarded as safe) organisms. Certain strains of Lactobacillus can colonize the gut, and are believed to show healthpromoting activities for humans and animals. Lactobacillus species have the capacity to evoke a mucosal as well as a systemic immune response against epitopes associated with these organisms after oral or nasal administration. These findings and earlier observations indicating that certain Lactobacillus species show a nonspecific immunoadjuvant effect by triggering of macrophages have prompted research aimed at investigating the potential of these organisms to synthesize foreign antigens and present them to the immune system. This chapter presents the construction and evaluation of a series of expression-secretion vectors with strong constitutive or regulatable promoters and efficient translation initiation regions designed for intra- and extracellular expression of homologous and heterologous proteins.