Lactic acid bacteria vector vaccines

Abstract

Vaccines are currently being developed based on the new concept of designing antigens that can prompt the innate immune system to trigger adaptive immunity and to characterize the T cells that are needed for the desired response. To develop protective immune responses against mucosal pathogens, the delivery route and adjuvants for vaccination are important. The host, however, strives to maintain mucosal homeostasis by responding to mucosal antigens with tolerance. This induction of mucosal immunity through vaccination is a rather difficult task. However, potent mucosal adjuvants, vectors, and other special delivery systems can be used. There is a great need to develop effective mucosal delivery systems that avoid degradation and promote uptake of the antigen in the gastrointestinal tract and stimulate adaptive immune responses, rather than the tolerogenic immune responses seen in studies done with feeding soluble antigens. Lactic acid bacteria have Generally Recognized As Safe (GRAS) status and have been developed in the past decade as potent adjuvants for mucosal delivery of vaccine antigens. Both Lactococcus lactis and Lactobacillus spp. have been used. In this chapter I will review the development of a platform technology based in Lactobacillus plantarum to deliver prophylactic molecules orally and will provide an example for plague.