Anamnestic protective immunity to Bacillus anthracis is antibody mediated but independent of complement and Fc receptors.
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.
Harvill
Eric T
ET
Department of Veterinary and Biomedical Science, The Pennsylvania State University, 115 Henning Building, University Park, Pennsylvania 16802, USA.
Osorio
Manuel
M
Loving
Crystal L
CL
Lee
Gloria M
GM
Kelly
Vanessa K
VK
Merkel
Tod J
TJ
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
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011961:Receptors, Fc; D003165:Complement System Proteins