| Title | Recognition of the carbohydrate modifications to the RgpA protease of Porphyromonas gingivalis by periodontal patient serum IgG. | | Author(s) | Slaney JM, Rangarajan M, Aduse-Opoku J, Fawell S, Darby I, Kinane D, Curtis MA | | Institution | Department of Medical Microbiology, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, UK. | | Source | J Periodontal Res 2002 Jun; 37(3):215-22. | | MeSH | Adhesins, Bacterial
Adult
Aged
Antibodies, Bacterial
Antigenic Modulation
Bacterial Proteins
Bacteroidaceae Infections
Cysteine Endopeptidases
Enzyme-Linked Immunosorbent Assay
Female
Hemagglutinins
Humans
Immunoglobulin G
Immunologic Surveillance
Lipopolysaccharides
Male
Middle Aged
Periodontitis
Polysaccharides
Porphyromonas gingivalis
| | Abstract | Periodontal infections by Porphyromonas gingivalis are associated with a sustained systemic IgG antibody response and elevations in local antibody synthesis to this organism. One of the targets of this response is a protease, RgpAcat, which is an important virulence determinant of this organism. Recently, we demonstrated that this molecule is glycosylated and that the glycan chains are immunologically related to P. gingivalis lipopolysaccharide (LPS) (Curtis et al., Infect Immun 1999;62:3816-3823). In the present study, we examined the role of these glycan additions in the immune recognition of RgpAcat, by sera from adult periodontal patients (n = 25). Serum IgG antibody levels to P. gingivalis W50, RgpAcat and LPS and to recombinant RgpA were determined by enzyme-linked immunosorbant assay (ELISA). No correlation was observed between the antibody levels to RgpAcat from P. gingivalis and the recombinant form of this enzyme expressed in Escherichia coli. However, a strong association was found between the recognition of LPS and the wild-type enzyme (R = 0.8926; p = 0.0005). Incorporation of LPS into the ELISA led to a significant reduction (mean 25%; range 0.8-43%, SD = 15; p < 0.05) in the recognition of RgpAcat, but had no effect on the recognition of control antigens. Deglycosylation of RgpAcat led to the abolition of immune recognition by patient serum IgG, which suggests that the glycan additions to this molecule are the principal targets of the immune response. Therefore, glycosylation of the RgpAcat protease may play an important role in immune evasion by shielding the primary structure from immune recognition. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
| | PubMed ID | 12113557 |
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