Cytokine production induced by non-encapsulated and encapsulated Porphyromonas gingivalis strains.
OBJECTIVE
Although the exact reason is not known, encapsulated gram-negative Porphyromonas gingivalis strains are more virulent than non-encapsulated strains. Since difference in virulence properties may be due to difference in cytokine production following recognition of the bacteria or their products by the host inflammatory cells, we compared cytokine production following stimulation with bacteria or lipopolysaccharides (LPS) of a non-encapsulated and an encapsulated P. gingivalis strain (K(-) and K1).


METHODS
Tumour necrosis factor-alpha (TNF-α) production following stimulation of the cell-line Mono Mac 6 with bacteria or LPS of both P. gingivalis strains was determined using flow cytometry. Furthermore, we investigated the effects of the two P. gingivalis strains or their LPS on TNF-α and Interleukin (IL-1β, IL-6, IL-12 and IL-10) production in whole blood using Luminex. In both experiments, Escherichia coli bacteria and LPS were used as a reference.


RESULTS
Both P. gingivalis strains induced lower cytokine production than E. coli with the exception of IL-6. P. gingivalis K1 bacteria elicited a higher overall cytokine production than P. gingivalis K(-). In contrast, P. gingivalis K1 LPS stimulation induced a lower cytokine production than P. gingivalis K(-) LPS.


CONCLUSIONS
Our findings suggest that the encapsulated P. gingivalis K1 bacteria induce higher cytokine production than the non-encapsulated P. gingivalis K(-). This was not due to its LPS. The stronger induction of cytokines may contribute to the higher virulence of P. gingivalis K1.
Department of Periodontology, Center for Dentistry and Oral Hygiene, University Medical Center Groningen and University of Groningen, The Netherlands. a.kunnen@umcg.nl
Alina
A
Kunnen
Daphne C
DC
Dekker
Maria G
MG
van Pampus
Hermie J M
HJ
Harmsen
Jan G
JG
Aarnoudse
Frank
F
Abbas
Marijke M
MM
Faas
D000328:Adult; D019540:Area Under Curve; D002460:Cell Line; D004926:Escherichia coli / Q000472:pathogenicity*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis* / Q000097:blood; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000472:pathogenicity*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000097:blood; D014774:Virulence
D007378:Interleukins; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha