title: Cutting Edge: IFN-gamma-producing CD4 T lymphocytes mediate spore-induced immunity to capsulated Bacillus anthracis.
abstract: Virulent strains of Bacillus anthracis produce immunomodulating toxins and an antiphagocytic capsule. The toxin component-protective Ag is a key target of the antianthrax immune response that induces production of toxin-neutralizing Abs. Coimmunization with spores enhances the antitoxin vaccine, and inactivated spores alone confer measurable protection. We aimed to identify the mechanisms of protection induced in inactivated-spore immunized mice that function independently of the toxin/antitoxin vaccine system. This goal was addressed with humoral and CD4 T lymphocyte transfer, in vivo depletion of CD4 T lymphocytes and IFN-gamma, and Ab-deficient (muMT(-/-)) or IFN-gamma-insensitive (IFN-gammaR(-/-)) mice. We found that humoral immunity did not protect from nontoxinogenic capsulated bacteria, whereas a cellular immune response by IFN-gamma-producing CD4 T lymphocytes protected mice. These results are the first evidence of protective cellular immunity against capsulated B. anthracis and suggest that future antianthrax vaccines should strive to augment cellular adaptive immunity.
authors.affiliation: Unité des Toxines et Pathogénie Bactérienne, Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France.
authors.forename: Ian Justin
authors.initials: IJ
authors.lastname: Glomski
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Corre
authors.forename: Michèle
authors.initials: M
authors.lastname: Mock
authors.forename: Pierre Louis
authors.initials: PL
authors.lastname: Goossens
mesh_terms: D000818:Animals; D000881:Anthrax / Q000276:immunology* / Q000517:prevention & control; D022122:Anthrax Vaccines / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000235:genetics / Q000276:immunology; D000917:Antibody Formation; D001408:Bacillus anthracis / Q000276:immunology*; D016667:Bacterial Capsules / Q000276:immunology*; D005260:Female; D007111:Immunity, Cellular; D007114:Immunization; D007371:Interferon-gamma / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D017471:Receptors, Interferon / Q000172:deficiency / Q000276:immunology; D013171:Spores, Bacterial / Q000276:immunology*; D000096743:Interferon gamma Receptor
chemical_list: D022122:Anthrax Vaccines; D000907:Antibodies, Bacterial; D007371:Interferon-gamma; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor