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Porphyromonas gingivalis surface components induce interleukin-1 release and tyrosine phosphorylation in macrophages
A Saito1, H T Sojar, R J Genco
1Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo 14214-3092, USA.
Abstract:
The aim of the present study was to characterize the responses of macrophages to surface antigens of Porphyromonas gingivalis. Native fimbriae, full-length recombinant fimbrillin, and a lectin-like 12-kDa antigen all stimulated BALB/c peritoneal macrophages to secrete interleukin (IL)-1 beta. The antigens induced similar patterns of tyrosine phosphorylation; proteins in approximately 35-46 kDa range of undetermined identities were phosphorylated in the macrophages. The abilities of the surface antigens to induce IL-1 beta were markedly attenuated by tyrosine kinase inhibitors. This inhibition correlated with inhibition of the induced phosphorylation of specific macrophage proteins at tyrosine. The data suggest that tyrosine kinase(s) plays an important role in the regulatory intracellular signaling mechanisms by which P. gingivalis surface antigens can mediate certain responses in macrophages.
Insights
Porphyromonas gingivalis surface antigens trigger macrophages to release interleukin-1 beta. This process involves tyrosine phosphorylation, indicating a key role for tyrosine kinases in macrophage signaling.
Area of Science:
- Immunology
- Microbiology
- Cellular Biology
Background:
- Porphyromonas gingivalis is a key pathogen in periodontitis.
- Macrophage activation is crucial in the host response to bacterial infections.
Purpose of the Study:
- To investigate macrophage responses to P. gingivalis surface antigens.
- To elucidate the intracellular signaling pathways involved in macrophage activation by these antigens.
Main Methods:
- BALB/c peritoneal macrophages were stimulated with P. gingivalis native fimbriae, recombinant fimbrillin, and a 12-kDa antigen.
- Interleukin-1 beta secretion was measured.
- Tyrosine phosphorylation patterns were analyzed using Western blotting.
- The effect of tyrosine kinase inhibitors on IL-1 beta secretion and phosphorylation was assessed.
Main Results:
- P. gingivalis antigens stimulated macrophages to secrete interleukin-1 beta (IL-1 beta).
- Antigens induced tyrosine phosphorylation of specific macrophage proteins (35-46 kDa).
- Tyrosine kinase inhibitors significantly reduced IL-1 beta secretion and phosphorylation.
Conclusions:
- Tyrosine kinases are critical mediators of intracellular signaling pathways activated by P. gingivalis surface antigens in macrophages.
- These signaling events are essential for the induction of IL-1 beta secretion by macrophages.