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Complement factor D-like activity of Porphyromonas gingivalis W83.
1Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond.
Oral Microbiology and Immunology
|August 1, 1991
Summary
Porphyromonas gingivalis strain W83 activates complement C3 in serum via a factor D-like protease. This mechanism allows bacterial survival by preventing C3 accumulation on the cell surface.
Area of Science:
- Immunology
- Microbiology
- Oral Health
Background:
- Porphyromonas gingivalis is linked to periodontal disease.
- P. gingivalis strain W83 inactivates complement C3 in human serum.
- Its complement inactivation mechanism is not fully understood.
Purpose of the Study:
- To investigate if P. gingivalis W83 possesses protease activity mimicking complement factor D.
- To determine if this activity facilitates C3 activation without significant C3 surface accumulation.
Main Methods:
- Incubation of P. gingivalis W83 with factor D-depleted serum and protease inhibitor TLCK.
- Incubation with purified complement C3 and factor B.
- Analysis of C3 consumption and inhibition by EDTA, TLCK, and factor H.
Main Results:
- C3 consumption in factor D-depleted serum was reversed by TLCK.
- P. gingivalis W83 with C3 and factor B showed increased C3 consumption.
- This consumption was inhibited by EDTA, TLCK, and factor H, suggesting C3 convertase formation.
Conclusions:
- P. gingivalis W83 likely possesses a factor D-like protease activity.
- This activity contributes to complement C3 activation and evasion of immune detection in periodontal disease.