DNA vaccines expressing pneumococcal surface protein A (PspA) elicit protection levels comparable to recombinant protein.
Pneumococcal surface protein A (PspA) is a promising candidate for the development of cost-effective vaccines against Streptococcus pneumoniae. In the present study, BALB/c mice were immunized with DNA vaccine vectors expressing the N-terminal region of PspA. Animals immunized with a vector expressing secreted PspA developed higher levels of antibody than mice immunized with the vector expressing the antigen in the cytosol. However, both immunogens elicited similar levels of protection against intraperitoneal challenge. Furthermore, immunization with exactly the same fragment in the form of a recombinant protein, with aluminium hydroxide as an adjuvant, elicited even higher antibody levels, but this increased humoral response did not correlate with enhanced protection. These results show that DNA vaccines expressing PspA are able to elicit protection levels comparable to recombinant protein, even though total anti-PspA IgG response is considerably lower.
Ferreira
Daniela M
DM
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Miyaji
Eliane N
EN
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Oliveira
Maria Leonor S
MLS
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Darrieux
Michelle
M
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Arêas
Ana Paula M
APM
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Ho
Paulo L
PL
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
Leite
Luciana C C
LCC
Centro de Biotecnologia, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil.
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology*; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D011008:Pneumococcal Infections / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage* / Q000276:immunology*; D019444:Vaccines, DNA / Q000235:genetics* / Q000276:immunology*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D011994:Recombinant Proteins; D019444:Vaccines, DNA; C051592:pneumococcal surface protein A