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Analysis of serum cross-reactivity and cross-protection elicited by immunization with DNA vaccines against Streptococcus pneumoniae expressing PspA fragments from different clades.
- Source :
-
Infection and immunity [Infect Immun] 2002 Sep; Vol. 70 (9), pp. 5086-90. - Publication Year :
- 2002
-
Abstract
- Streptococcus pneumoniae is a major cause of disease, especially in developing countries, and cost-effective alternatives to the currently licensed vaccines are needed. We constructed DNA vaccines based on pneumococcal surface protein A (PspA), an antigen shown to induce protection against pneumococcal bacteremia. PspA fragments can be divided into three families, which can be subdivided into six clades, on the basis of PspA amino acid sequence divergence (S. K. Hollingshead, R. Becker, and D. E. Briles, Infect. Immun. 68:5889-5900, 2000). Since most clinical isolates belong to family 1 or family 2, PspA fragments from members of both of these families were analyzed. Vectors encoding the complete N-terminal regions of PspAs elicited significant humoral responses, and cross-reactivity was mainly restricted to the same family. DNA vaccines encoding fusions between PspA fragments from family 1 and family 2 were also constructed and were able to broaden the cross-reactivity, with induction of antibodies that showed reactions with members of both families. At least for the pneumococcal strains tested, the cross-reactivity of antibodies was not reflected in cross-protection. Animals immunized with DNA vaccines expressing the complete N-terminal regions of PspA fragments were protected only against intraperitoneal challenge with a strain expressing PspA from the same clade.
- Subjects :
- Animals
Antibodies, Bacterial blood
Antigens, Bacterial chemistry
Antigens, Bacterial genetics
Bacterial Proteins chemistry
Base Sequence
Cloning, Molecular
Cross Reactions
DNA, Bacterial genetics
Female
Immunization
Immunoglobulin G blood
Mice
Mice, Inbred BALB C
Peptide Fragments chemistry
Peptide Fragments genetics
Peptide Fragments immunology
Pneumococcal Infections immunology
Pneumococcal Infections prevention & control
Bacterial Proteins genetics
Bacterial Proteins immunology
Pneumococcal Vaccines genetics
Pneumococcal Vaccines immunology
Streptococcus pneumoniae genetics
Streptococcus pneumoniae immunology
Vaccines, DNA genetics
Vaccines, DNA immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0019-9567
- Volume :
- 70
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Infection and immunity
- Publication Type :
- Academic Journal
- Accession number :
- 12183557
- Full Text :
- https://doi.org/10.1128/IAI.70.9.5086-5090.2002