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Pathogenic mechanisms induced by microbial proteases in microbial infections
1Department of Microbiology, Kumamoto University School of Medicine, Japan.
Biological Chemistry Hoppe-Seyler
|April 1, 1996
Summary
Microbial proteases significantly enhance disease severity by triggering kinin generation and degrading host defenses. These proteases resist and inactivate host inhibitors, promoting bacterial spread and septicemia.
Area of Science:
- Microbiology
- Immunology
- Biochemistry
Background:
- Bacterial and fungal proteases contribute to pathogenesis by causing symptoms like pain, edema, and septicemia.
- A key mechanism involves kinin generation, either directly or via the bradykinin cascade (Hageman factor, prekallikrein, kallikrein).
Purpose of the Study:
- To elucidate the pathogenic mechanisms of microbial proteases in host infections.
- To highlight the role of microbial proteases in immune evasion and disease progression.
Main Methods:
- The study reviews the biochemical interactions between microbial proteases and host systems.
- Analysis of protease resistance to host inhibitors (serpins) and their effects on host zymogens.
Main Results:
- Microbial proteases activate the bradykinin cascade, degrade immunoglobulins and complement, and inactivate host protease inhibitors (serpins).
- Bacterial cell wall components (endotoxin, teichoic acid) also activate the bradykinin cascade.
- These actions facilitate bacterial translocation, septicemia, and overall pathogenesis.
Conclusions:
- Microbial proteases are critical virulence factors that significantly enhance the pathogenesis of severe infections.
- Understanding these mechanisms is vital for developing targeted therapies against microbial proteases.