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Immunological cross-reactivity between outer membrane pore proteins of Campylobacter jejuni and Escherichia coli
M Kervella1, J L Fauchère, D Fourel
1Laboratoire de Bactériologie, Faculté de Médecine, Necker-Enfants Malades, Paris, France.
Abstract:
Immunocrossreactivity between the major outer membrane protein (MOMP) of Campylobacter jejuni 85H and the OmpC porin of Escherichia coli K-12 was observed. These results indicate that a common antigenic domain is conserved in both MOMP and OmpC. This antigenic region is detected only after a 96 degrees C treatment suggesting that it is buried in the native conformation of the respective porins. In addition, differences were observed between the major outer membrane proteins from various C. jejuni strains. About 60% of the C. jejuni pathogenic strains tested contained a protein exhibiting a similar electrophoretic profile to the 85H porin.
Insights
A shared antigenic site exists between Campylobacter jejuni major outer membrane protein (MOMP) and E. coli OmpC porin. This site is hidden in native proteins but revealed after heat treatment, indicating conserved bacterial outer membrane protein structures.
Area of Science:
- Microbiology
- Immunology
- Structural Biology
Background:
- The major outer membrane protein (MOMP) is crucial for bacterial structure and pathogenicity.
- Porins, like E. coli OmpC, form channels in the outer membrane, facilitating molecular transport.
- Understanding conserved antigenic domains in bacterial outer membrane proteins is vital for vaccine development.
Purpose of the Study:
- To investigate potential immunocrossreactivity between Campylobacter jejuni MOMP and E. coli OmpC.
- To identify conserved antigenic regions within these bacterial outer membrane proteins.
- To explore variations in MOMP among different C. jejuni strains.
Main Methods:
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to analyze protein profiles.
- Heat treatment (96°C) to assess antigen exposure.
- Immunological assays to detect cross-reactivity between C. jejuni and E. coli proteins.
Main Results:
- Significant immunocrossreactivity was observed between C. jejuni 85H MOMP and E. coli K-12 OmpC.
- A common, heat-masked antigenic domain was identified in both MOMP and OmpC.
- Approximately 60% of pathogenic C. jejuni strains possessed MOMP similar to the 85H strain.
Conclusions:
- A conserved antigenic domain exists in the major outer membrane proteins of C. jejuni and E. coli.
- This domain is typically buried in the native protein structure and becomes accessible upon denaturation.
- Variability in MOMP exists among C. jejuni strains, with a common variant prevalent in pathogenic isolates.