Lactic acid bacteria — promising vaccine vectors: possibilities, limitations, doubts

Abstract

Gram-positive and nonpathogenic lactic acid bacteria (LAB) are considered to be promising candidates for the development of new, safe systems of heterologous protein expression. Additionally, many experiments have shown that specific systemic and mucosal immune responses against selected pathogens can be elicited using modified LAB strains. For that reason they could be a good replacement of classical, often pathogenic, attenuated carriers. This solution offers many advantages in comparison to systemic inoculation, as well as, from immunological and practical points of view. The development of efficient mucosal vaccines is nowadays a priority in modern vaccinology, together with improvement of immunization efficiency, monitoring of antigen production in vivo, determination of optimal dose for vaccination, strain selection and characterization.