Effect of oral bacteria on peripheral blood leukocyte interleukin-6 and soluble interleukin-6 receptor production.
To determine the effect of pathogenic oral bacteria on interleukin 6 (IL-6) and soluble IL-6 receptor production, we measured their release by human peripheral blood mononuclear cells in vitro. Unseparated peripheral blood mononuclear cells, peripheral blood lymphocytes (monocyte depleted), pure T cells, or monocytes were cultured with Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, Capnocytophaga ochracea, Fusobacterium nucleatum or Porphyromonas gingivalis for 24 h. Supernatants were tested for IL-6 and soluble IL-6 receptor by enzyme-linked immunosorbent assay. Only monocytes and peripheral blood mononuclear cells responded with significant IL-6 release in the presence of all bacteria tested. However, peripheral blood lymphocytes were capable of producing IL-6 when activated by phytohemagglutinin or IL-2 followed by bacteria, though substantially less than cultures containing monocytes. No bacteria tested increased soluble IL-6 receptor release over spontaneous soluble IL-6 receptor release. We conclude that monocytes release IL-6 after contact with oral pathogens; however, soluble IL-6 receptor from T cells and monocytes is constitutively produced and may modulate IL-6 actions.
Lindemann
R A
RA
Section of Oral Biology, UCLA School of Dentistry 90095-1668, USA.
Kinder Haake
S A
SA
Kjeldsen
M
M
Avanessian
A B
AB
D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology; D000818:Animals; D002206:Capnocytophaga / Q000276:immunology; D016967:Fusobacterium nucleatum / Q000276:immunology; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008214:Lymphocytes / Q000378:metabolism*; D008252:Macaca fascicularis; D009000:Monocytes / Q000378:metabolism*; D010518:Periodontitis / Q000276:immunology* / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000276:immunology; D018123:Receptors, Interleukin / Q000096:biosynthesis*
D015850:Interleukin-6; D018123:Receptors, Interleukin