Utilizing Salmonella for antigen delivery: the aims and benefits of bacterial delivered vaccination

Abstract

vac-cines (RASVs) that synthesize protective antigens have been and are being devel-oped to provide novel, needle-free, low-cost protection against various diseases. RASVs are constructed so that, following oral immunization, attenuation does not diminish the strains’ abilities to survive stresses encountered in the GI tract nor to colonize lymphoid tissues. Attenuation precludes RASVs from causing disease but the RASVs are fully capable of eliciting immune responses to result in long-lasting protection. Researchers in the Curtiss lab -oratory have developed RASVs featuring regulated delayed expression of attenua-tion, regulated delayed synthesis of recom -binant antigens and regulated delayed lysis. These RASVs induced mucosal, sys -temic and cellular immune responses in mice against viral, bacterial and parasite pathogens.Vaccines are the most effective means to prevent infectious diseases. Key to a good vaccine is the ability to induce long-term protective immunity against a specific pathogen. Bacterial vaccine vectors have been used to impart protection against self as well as heterologous antigens. A sig -nificant benefit of using live bacterial vac -cine vectors is their ability to invade and colonize deep effector lymphoid tissues after mucosal delivery, which is critically important for inducing memory T cells;