title: PsaA (pneumococcal surface adhesin A) and PspA (pneumococcal surface protein A) DNA vaccines induce humoral and cellular immune responses against Streptococcus pneumoniae.
abstract: Streptococcus pneumoniae is one of the most important human pathogens and improvement of the currently used polysaccharide vaccines is being pursued. We constructed DNA vaccine vectors containing either the full-length psaA (pneumococcal surface adhesin A) or a truncated pspA (pneumococcal surface protein A--pspA') gene. Both constructs showed transient expression of the antigens in vertebrate cells and induced significant antibody response to the pneumococcal antigens in BALB/c mice injected intramuscularly (i.m.). Fusion with an N-terminal cytoplasmatic SV40 T-antigen (CT-Ag), which was previously shown to stabilize poorly expressed antigens through association with Hsp73, also induced anti-PspA antibody response. The induction of antibodies with a low IgG1:IgG2a ratio and elevated gamma interferon (IFN-gamma) production by spleen cells elicited by DNA vaccination indicate preferential priming of Th1 immunity. Since induction of antibodies against both PsaA and PspA was previously shown to correlate with protection against fatal infection with S. pneumoniae and cell-mediated immune responses could contribute to protection, further evaluation of PsaA and PspA as antigens for a DNA vaccine against S. pneumoniae could be promising.
authors.affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil. enmiyaji@uol.com.br
authors.forename: E N
authors.initials: EN
authors.lastname: Miyaji
authors.forename: W O
authors.initials: WO
authors.lastname: Dias
authors.forename: M
authors.initials: M
authors.lastname: Gamberini
authors.forename: V C
authors.initials: VC
authors.lastname: Gebara
authors.forename: R P
authors.initials: RP
authors.lastname: Schenkman
authors.forename: J
authors.initials: J
authors.lastname: Wild
authors.forename: P
authors.initials: P
authors.lastname: Riedl
authors.forename: J
authors.initials: J
authors.lastname: Reimann
authors.forename: R
authors.initials: R
authors.lastname: Schirmbeck
authors.forename: L C
authors.initials: LC
authors.lastname: Leite
mesh_terms: D018829:Adhesins, Bacterial; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology*; D004269:DNA, Bacterial / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008074:Lipoproteins / Q000235:genetics / Q000276:immunology*; D026901:Membrane Transport Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D022242:Pneumococcal Vaccines / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology / Q000494:pharmacology
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D006360:Heat-Shock Proteins; D008074:Lipoproteins; D026901:Membrane Transport Proteins; D022242:Pneumococcal Vaccines; C085000:PsaA protein, Streptococcus; D019444:Vaccines, DNA; C069816:phage shock protein, Bacteria; D015847:Interleukin-4; D007371:Interferon-gamma