title: Anamnestic protective immunity to Bacillus anthracis is antibody mediated but independent of complement and Fc receptors.
abstract: The threat of bioterrorist use of Bacillus anthracis has focused urgent attention on the efficacy and mechanisms of protective immunity induced by available vaccines. However, the mechanisms of infection-induced immunity have been less well studied and defined. We used a combination of complement depletion along with immunodeficient mice and adoptive transfer approaches to determine the mechanisms of infection-induced protective immunity to B. anthracis. B- or T-cell-deficient mice lacked the complete anamnestic protection observed in immunocompetent mice. In addition, T-cell-deficient mice generated poor antibody titers but were protected by the adoptive transfer of serum from B. anthracis-challenged mice. Adoptively transferred sera were protective in mice lacking complement, Fc receptors, or both, suggesting that they operate independent of these effectors. Together, these results indicate that antibody-mediated neutralization provides significant protection in B. anthracis infection-induced immunity.
authors.affiliation: Department of Veterinary and Biomedical Science, The Pennsylvania State University, 115 Henning Building, University Park, Pennsylvania 16802, USA.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Harvill
authors.forename: Manuel
authors.initials: M
authors.lastname: Osorio
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Loving
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Lee
authors.forename: Vanessa K
authors.initials: VK
authors.lastname: Kelly
authors.forename: Tod J
authors.initials: TJ
authors.lastname: Merkel
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D001408:Bacillus anthracis / Q000276:immunology*; D003165:Complement System Proteins / Q000276:immunology*; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011961:Receptors, Fc / Q000172:deficiency / Q000276:immunology*; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011961:Receptors, Fc; D003165:Complement System Proteins