title: Protective effect of Bacillus anthracis surface protein EA1 against anthrax in mice.
abstract: Bacillus anthracis spores germinate to vegetative forms in host cells, and produced fatal toxins. A toxin-targeting prophylaxis blocks the effect of toxin, but may allow to grow vegetative cells which create subsequent toxemia. In this study, we examined protective effect of extractable antigen 1 (EA1), a major S-layer component of B. anthracis, against anthrax. Mice were intranasally immunized with recombinant EA1, followed by a lethal challenge of B. anthracis spores. Mucosal immunization with EA1 resulted in a significant level of anti-EA1 antibodies in feces, saliva and serum. It also delayed the onset of anthrax and remarkably decreased the mortality rate. In addition, the combination of EA1 and protective antigen (PA) protected all immunized mice from a lethal challenge with B. anthracis spores. The numbers of bacteria in tissues of EA1-immunized mice were significantly decreased compared to those in the control and PA alone-immunized mice. Immunity to EA1 might contribute to protection at the early phase of infection, i.e., before massive multiplication and toxin production by vegetative cells. These results suggest that EA1 is a novel candidate for anthrax vaccine and provides a more effective protection when used in combination with PA.
authors.affiliation: Laboratory of Food Microbiology and Immunology, Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchida
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Harada
authors.forename: Jargalsaikhan
authors.initials: J
authors.lastname: Enkhtuya
authors.forename: Akiko
authors.initials: A
authors.lastname: Kusumoto
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Shiori
authors.initials: S
authors.lastname: Chiba
authors.forename: Anselme
authors.initials: A
authors.lastname: Shyaka
authors.forename: Keiko
authors.initials: K
authors.lastname: Kawamoto
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000881:Anthrax / Q000517:prevention & control*; D022122:Anthrax Vaccines / Q000008:administration & dosage / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology
chemical_list: D022122:Anthrax Vaccines; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D011994:Recombinant Proteins