title: Protective immunogenicity of two synthetic peptides selected from the amino acid sequence of Bordetella pertussis toxin subunit S1.
abstract: Two peptides, corresponding to amino acids 1-17 and 169-186 of the amino acid sequence of pertussis toxin (PT) subunit S1, were synthesized and coupled to the diphtheria toxin cross-reactive mutant protein CRM 197 and evaluated for immunogenicity and protective capacity against PT challenge in vivo. The peptide-CRM conjugates induced high antibody titers against native toxin in mice (BALB/c, C57/Black, and outbred NMRI) as measured by ELISA. Upon PT challenge (0.5 microgram of toxin) of the NMRI mice, the CRM conjugates of peptides 1-17 and 169-186 fully protected the mice from PT-induced leukocytosis. Immunization with the corresponding bovine serum albumin conjugates of these two peptides also fully protected mice. Rabbit antiserum to the peptide 1-17-CRM conjugate was highly efficient in inhibiting the ADP-ribosylating activity of PT but did not neutralize the clustering effect of PT on Chinese hamster ovary cells. In contrast, the rabbit antiserum raised against the peptide 169-186-CRM conjugate neutralized the clustering effect of PT on Chinese hamster ovary cells but did not inhibit the enzymatic activity of PT. Peptide 169-186-CRM conjugates mimic the immunoglobulin binding properties of PT and also cause clustering of Chinese hamster ovary cells. The CRM conjugates of these two peptides constitute a synthetic pertussis vaccine candidate with the ability to provide a chemically well-defined, safe, and efficient pertussis vaccine.
authors.affiliation: National Bacteriological Laboratory, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Askelöf
authors.forename: K
authors.initials: K
authors.lastname: Rodmalm
authors.forename: G
authors.initials: G
authors.lastname: Wrangsell
authors.forename: U
authors.initials: U
authors.lastname: Larsson
authors.forename: S B
authors.initials: SB
authors.lastname: Svenson
authors.forename: J L
authors.initials: JL
authors.lastname: Cowell
authors.forename: A
authors.initials: A
authors.lastname: Undén
authors.forename: T
authors.initials: T
authors.lastname: Bartfai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D000917:Antibody Formation; D004167:Diphtheria Toxin / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D007114:Immunization; D046911:Macromolecular Substances; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009154:Mutation; D009243:NAD / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000276:immunology*; D014917:Whooping Cough / Q000517:prevention & control
chemical_list: D000907:Antibodies, Bacterial; D004167:Diphtheria Toxin; D046911:Macromolecular Substances; D010455:Peptides; D010566:Virulence Factors, Bordetella; D009243:NAD; D037342:Pertussis Toxin