Induction of immune responses by attenuated isogenic mutant strains of Listeria monocytogenes

• Published in: Vaccine Vol. 21; no. S2; pp. S102 - S109
• Main Authors: Darji, Ayub, Mohamed, Walid, Domann, Eugen, Chakraborty, Trinad
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2003; Elsevier Limited
• Subjects: Animals; Bacteria; Bacterial Vaccines - immunology; Bacteriology; CD8-Positive T-Lymphocytes - immunology; Cytokines - biosynthesis; Female; Genes; Genetic engineering; Immunization; Infections; Isogenic L. monocytogenes mutants; L-Selectin - analysis; Listeria; Listeria monocytogenes; Listeria monocytogenes - immunology; Lymphocytes; Mice; Mice, Inbred BALB C; Microorganisms; Mutants; Mutation; Protection; Studies; Vaccine; Vaccines, Attenuated - immunology; Viral infections; Isogenic L. monocytogenes mutants; Protection; Vaccine
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(03)00208-1

We have generated isogenic Listeria monocytogenes mutant strains to study the induction of protective immunity in mice. These strains harbored either a specific deletion within the actin nucleator ( actA) and/or have multiple deletions within the actA and phospholipase B ( plcB) genes. In comparison to the wild type parental L. monocytogenes EGDe strains, the mutant strains were extremely low in virulence and were rapidly eliminated by the host during the first days of infection. Nevertheless, a single immunization with both mutant strains (EGDe Δ actA2 and Δ actAΔ plcB) efficiently induced and maintained effector memory (CD8 +) T cells and has provided animals with a state of long-lasting protective immunity against wild type L. monocytogenes. These mutant strains can be used as live vaccines against the corresponding virulent pathogen and as carriers for introducing heterologous protective antigens into animals and humans.