title: Nontoxigenic protein A vaccine for methicillin-resistant Staphylococcus aureus infections in mice.
abstract: The current epidemic of hospital- and community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections has caused significant human morbidity, but a protective vaccine is not yet available. Prior infection with S. aureus is not associated with protective immunity. This phenomenon involves staphylococcal protein A (SpA), an S. aureus surface molecule that binds to Fcgamma of immunoglobulin (Ig) and to the Fab portion of V(H)3-type B cell receptors, thereby interfering with opsonophagocytic clearance of the pathogen and ablating adaptive immune responses. We show that mutation of each of the five Ig-binding domains of SpA with amino acid substitutions abolished the ability of the resulting variant SpA(KKAA) to bind Fcgamma or Fab V(H)3 and promote B cell apoptosis. Immunization of mice with SpA(KKAA) raised antibodies that blocked the virulence of staphylococci, promoted opsonophagocytic clearance, and protected mice against challenge with highly virulent MRSA strains. Furthermore, SpA(KKAA) immunization enabled MRSA-challenged mice to mount antibody responses to many different staphylococcal antigens.
authors: Department of Microbiology, University of Chicago, Chicago, IL 60637.
authors: Hwan Keun
authors: HK
authors: Kim
authors: Alice G
authors: AG
authors: Cheng
authors: Hye-Young
authors: HY
authors: Kim
authors: Dominique M
authors: DM
authors: Missiakas
authors: Olaf
authors: O
authors: Schneewind
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D017209:Apoptosis; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000276:immunology* / Q000472:pathogenicity; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013203:Staphylococcal Infections / Q000276:immunology*; D013205:Staphylococcal Protein A / Q000737:chemistry / Q000276:immunology*; D013209:Staphylococcal Vaccines / Q000276:immunology*; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D013205:Staphylococcal Protein A; D013209:Staphylococcal Vaccines