Characterization of genetically inactivated pertussis toxin mutants: candidates for a new vaccine against whooping cough

Nencioni, L; Pizza, Mariagrazia; Bugnoli, M; Magistris, T De; Tommaso, A. Di; Giovannoni, Franco; Manetti, Roberto; Marsili, I.; Matteucci, Giacomo; Nucci, Daniele

doi:10.1128/iai.58.5.1308-1315.1990

Cited by 108 publications

(61 citation statements)

References 48 publications

(40 reference statements)

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“…When tested for their ability to induce toxin-neutralizing antibodies, two doses of 3 /zg of these mutants were found to induce a toxin neutralizing titer > 1/1280, a value higher than that generally obtained with chemically detoxified PT. Finally, the same mutants were able to protect mice from the intracerebral challenge with virulent B. pertussis in a dose-dependent fashion [40]. Since this last test correlated with the efficacy in humans of the cellular vaccine, we concluded that the genetically detoxified PT molecules were excellent candidates for the development of acellular pertussis vaccines.…”

Section: Enzymatic Activitymentioning

confidence: 71%

Recombinant acellular pertussis vaccine — from the laboratory to the clinic: improving the quality of the immune response

Rappuoli¹

1992

FEMS Microbiology Letters

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Vaccination is the most effective way to prevent infectious diseases. Recombinant DNA technologies have provided powerful new tools to develop vaccines that were previously impossible or difficult to make, and to improve the vaccines that were already available but had been developed using old technology. In the case of whooping cough, an effective vaccine (composed of killed bacterial cells) is available, but its use is controversial because of the many side effects that have been associated with it. An improved vaccine against this disease should contain pertussis toxin, a molecule that needs to be detoxified in order to be included in the vaccine. Classical methods of detoxification, such as formaldehyde treatment have been used to inactivate this toxin. We have used recombinant DNA technologies to clone the pertussis toxin gene, express it in bacteria, map the B and T cell epitopes of the molecule, and to identify the amino acids that are important for enzymatic activity and toxicity. Finally, we have used this information to mutate the gene in the chromosome of Bordetella pertussis in order to obtain a strain that produces a molecule that is already non‐toxic. This genetically inactivated pertussis toxin was tested extensively in animal models and clinical trials and was found to induce an immune response that is superior in quality and quantity to that induced by the vaccines produced by conventional technologies.

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Section: Enzymatic Activitymentioning

confidence: 71%

Recombinant acellular pertussis vaccine — from the laboratory to the clinic: improving the quality of the immune response

Rappuoli¹

1992

FEMS Microbiology Letters

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“…PT is a poor T cell mitogen and, to give a mitogenic effect in vitro, it requires doses that are -103 -106 times higher than those of staphylococcal enterotoxins SEA, SEB, or TSST1 . In fact, the mitogenic dose of TSST1 is 1 pg/ml (25), 1 ng/ml for SEA and SEB (26), and 1 p,g/ml for PT (13). So far, the role in pathogenicity of the mitogenic effect of PT has never been investigated, because the toxicity of PT has always been attributed to the enzymatic activity of the S1 subunit .…”

Section: Discussionmentioning

confidence: 99%

Metabolic, humoral, and cellular responses in adult volunteers immunized with the genetically inactivated pertussis toxin mutant PT-9K/129G.

Podda¹,

Nencioni²,

Magistris³

et al. 1990

The Journal of Experimental Medicine

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SummaryPT9K/129G, a nontoxic mutant of pertussis toxin (PT) obtained by genetic manipulation, has been shown in animal models to be a promising candidate for new vaccines against whooping cough. To assess the safety and the immunogenicity of PT-9K/129G in humans, a pilot study has been performed in adult volunteers. The protein was found to be safe, capable of inducing high titers of toxin-neutralizing antibodies, and capable of generating immunological memory. In fact, vaccination caused an increase of cell-mediated response to PT, PT9K/129G, S1 subunit, and B oligomer, indicating that memory T cells are induced by the vaccine. Since PT-9K/129G is mitogenic for T lymphocytes in vitro, it was investigated whether this activity is also present in vivo. No variation was observed in the proportion of T cells (CD3'), T helper cells (CD4+), and cytotoxic T cells (CD8+), as well as in that of other lymphoid populations, by FACS analysis. Interestingly, no thorough correlation was found between humoral and cellular responses. In one case, a very high cellular response was present in absence of detectable antibodies, suggesting that the antibody response, which is the only parameter measured in most clinical trials, may not give a complete picture of the response induced by a vaccine.

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“…Yields were comparable to those of B. pertussis and although the majority of the PT produced was localised in the periplasm, PT was detected in the culture supernatant. B. parapertussis and B. bronchiseptica have also been used to produce genetically altered detoxi¢ed PT [166,167]. Bacterial strains engineered to produce a safe pertussis`toxoid' are very good candidates for the production of acellular vaccines.…”

Section: Pertussis Toxinmentioning

confidence: 99%

The virulence factors of Bordetella pertussis: a matter of control

Smith

2001

FEMS Microbiology Reviews

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Bordetella pertussis is the causative agent of whooping cough, a contagious childhood respiratory disease. Increasing public concern over the safety of whole-cell vaccines led to decreased immunisation rates and a subsequent increase in the incidence of the disease. Research into the development of safer, more efficacious, less reactogenic vaccine preparations was concentrated on the production and purification of detoxified B. pertussis virulence factors. These virulence factors include adhesins such as filamentous haemagglutinin, fimbriae and pertactin, which allow B. pertussis to bind to ciliated epithelial cells in the upper respiratory tract. Once attachment is initiated, toxins produced by the bacterium enable colonisation to proceed by interfering with host clearance mechanisms. B. pertussis co-ordinately regulates the expression of virulence factors via the Bordetella virulence gene (bvg) locus, which encodes a response regulator responsible for signal-mediated activation and repression. This strict regulation mechanism allows the bacterium to express different gene subsets in different environmental niches within the host, according to the stage of disease progression.

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Characterization of genetically inactivated pertussis toxin mutants: candidates for a new vaccine against whooping cough

Cited by 108 publications

References 48 publications

Recombinant acellular pertussis vaccine — from the laboratory to the clinic: improving the quality of the immune response

Recombinant acellular pertussis vaccine — from the laboratory to the clinic: improving the quality of the immune response

Metabolic, humoral, and cellular responses in adult volunteers immunized with the genetically inactivated pertussis toxin mutant PT-9K/129G.

The virulence factors of Bordetella pertussis: a matter of control

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