Les Bactéries lactiques nouveaux vecteurs vaccinaux

Abstract

This study demonstrates the effect of lactic bacteria use as vaccine vectors for the development of effective immunity against different bacterial or viral diseases. For this purpose, the analysis of the article by Wei et al. (2009): "Immunogenicity and Protective Effective Efficacy of Orally Gold intranasally administered recombinant Lactobacillus casei Expressing ETEC K99", is achieved to understand the mechanisms implemented for the use of lactic bacteria in the design of effective vaccines. The study of the article analyzed aims to develop a safe and effective vaccine for the prevention of enterotoxin Escherichia coli (ETEC) K99 responsible for several infectious diseases; A surface antigen display system using PGSA (poly - glutamate synthetase a) is expanded as anchor matrix. The recombinant fusion proteins consisting of PGSA and ETEEC K99 Fimbriae protein have been stably expressed on Lactobacillus Casei. The surface location of the fusion protein was verified by immunoblot, immunofluorescence microscopy and flow cytometry. BALB / C mouse free of specific pathogens (SPF) Oral or intranasal vaccinated with L. casei resulted in serum IMA immunoglobulin G (IgG) immunoglobulins against ETEEC K99, as demonstrated Immuno-enzyme tests using purified fimbria peptides. The serum antibody isotypes obtained were predominantly IgG1 and IgG2a. Spfbalb / cm mice vaccinated were evaluated by oral provocation with standard ETEEC C83912 after the last reminder vaccination. More than 80% of the immune mice survived regardless of the immune route. The antibody titers induced after oral immunization were lower than those after intranasal immunization but the protective efficiency was of the same order of magnitude. These results indicate that mucosal immunization with L. casei the expression of the Fimbriae ETEEC K99 protein at its surface provides an effective way to trigger a protective immune response against ETEEC K99.