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

Abstract

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.

The identification, cloning and mutagenesis of a genetic locus required for lipopolysaccharide biosynthesis in Bordetella pertussis

“…Bordetella pertussis is a Gram-negative bacterium that causes whooping cough in children. The surge of molecular biological research into the virulence and vaccinology of B. pertussis over the last few years has concentrated almost exclusively on proteins (Rappuoli et a/., 1992;Cherry, 1992) and little work has been done on non-protein structures that may be involved in the infectious process.…”

Identification and Cloning of waaF ( rfaF ) from Bordetella pertussis and Use To Generate Mutants of Bordetella spp. with Deep Rough Lipopolysaccharide

“…Bordetella bronchiseptica has only rarely been associated with human disease (13,34,42) and is more commonly known as a pathogen of a range of species, including rabbits, pigs, dogs, and cats, among others (1,5,17,23,35,43,44,49). In the search for improved modern vaccines directed against B. pertussis, a large body of work has been generated regarding protein virulence factors and targets for protective immunity (8,32). This has led to a relative lack of research into the lipopolysaccharide (LPS) molecule found on the bordetellae, which is highly biologically active as an endotoxin, an immunomodulator, and an antigen (3,7,48).…”

A mutant pertussis toxin molecule that lacks ADP-ribosyltransferase activity, PT-9K/129G, is an effective mucosal adjuvant for intranasally delivered proteins

“…Parenterally administered PTX can potentiate IgE and delayed-type hypersensitivity to coadministered proteins (23,41). PTX is one of the major protective antigens of B. pertussis, and inactivated forms of PTX form the basis of currently used and experimental acellular pertussis vaccines (31). A genetically detoxified form of PTX (PT-9K/129G) which lacks the deleterious properties of PTX but which can still bind to eucaryotic cells and is highly immunogenic in rodents and humans has been constructed (24,28,29,31).…”