Lack of protection of mice against Staphylococcus aureus despite a significant immune response to immunization with a DNA vaccine encoding collagen-binding protein.

Abstract

Collagen-binding protein (CNA) is the major Staphylococcus aureus adhesin responsible for high affinity binding to collagen and is assumed to be a major virulence factor in infection and disease. Mutants lacking the cna gene are less virulent than the parent strain in models of septic arthritis, osteomyelitis, keratinitis, and endocarditis. In order to investigate the immunological and protective properties of a CNA-based DNA vaccine, a eukaryotic expression vector pCNA was constructed which expressed the collagen-binding domain of this adhesin in transfected cells. Three groups of 11 Balb/c mice received three injection of either pCNA, the empty expression vector (pCI) or PBS. Those injected with pCNA showed hi titre (64000) antibody and evidence of a cell-mediated immune response (CMI). The anti-CNA antibodies recognized the intact bacteria and prevented binding to collagen in vitro. However, the vaccination did not protect against bacterial challenge using the intra-peritoneal route of infection. Moreover, S. aureus that had been treated with sera from vaccinated mice caused a more severe infection than bacteria treated with sera from non-vaccinated mice. In summary, DNA vaccination against CNA produced a strong antibody and cellular response in mice but failed to protect from i.p. infection by S. aureus.

• Authors: Roseline Therrien, Pierre Lacasse, Gilles Grondin, Brian G Talbot
• Journal: Vaccine (Vaccine) Vol. 25 Issue 27 Pg. 5053-61 (Jun 28 2007) ISSN: 0264-410X [Print] Netherlands
• PMID: 17532546 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adhesins, Bacterial
• Antibodies, Bacterial
• Immunoglobulin G
• Recombinant Proteins
• Staphylococcal Vaccines
• Vaccines, DNA
• adhesin, Staphylococcus aureus

Topics

• Adhesins, Bacterial (immunology)
• Animals
• Antibodies, Bacterial (biosynthesis, pharmacology)
• CD8-Positive T-Lymphocytes (immunology)
• COS Cells
• Cell Proliferation
• Chlorocebus aethiops
• Colony Count, Microbial
• Eukaryotic Cells
• Immunoglobulin G (immunology)
• Mice
• Peritonitis (immunology, microbiology)
• Plasmids (genetics)
• Recombinant Proteins (immunology)
• Staphylococcal Infections (immunology, microbiology, prevention & control)
• Staphylococcal Vaccines (immunology)
• Staphylococcus aureus (immunology)
• Vaccines, DNA (immunology)