TY - JOUR
T1 - Porphyromonas gingivalis culture supernatants differentially regulate Interleukin-1β and Interleukin-18 in human monocytic cells
AU - Hamedi, M.
AU - Belibasakis, G. N.
AU - Cruchley, A. T.
AU - Rangarajan, M.
AU - Curtis, M. A.
AU - Bostanci, N.
PY - 2009/2
Y1 - 2009/2
N2 - Porphyromonas gingivalis is a major bacterial species implicated in chornic periodontitis, a disease characterized by inflammatory destruction of the tooth supporting tissues. Its main virulence factors are lipopolysaccharide (LPS) and gingipains, a group of cysteine proteinases. Interleukin (IL)-18 is a potent pro-inflammatory cytokine with structural similarities to IL-1β. This study aimed to investigate if P .gingivalis regulates IL-1β and IL-18 in monocytic cells. Monomac-6 cells were challenged with P. gingivalis culture supernatants. Quantitative real-time PCR and ELISA were used to investigate IL-1β and IL-18 mRNA expression and protein secretion, respectively. P. gingivalis enhanced IL-1β and IL-18 mRNA expression, the former being induced earlier, but transiently. IL-18 up-regulation was not affected by P. gingivalis heat-inactivation or chemical inhibition of its gingipains, whereas both treatments resulted in 50% reduction of IL-1β expression. Purified P. gingivalis LPS enhanced both IL-1β and IL-18 expression. However, only IL-1β, but not IL-18, secretion was detected, and was up-regulated by P. gingivalis. In conclusion, although IL-1β and IL-18 belong to the same cytokine family, their gene expression and secretion are differentially regulated in human monocytic cells in response to P. gingivalis. Therefore, cytokines of the IL-1 family may participate via different pathways in the complex pathogenesis of periodontitis.
AB - Porphyromonas gingivalis is a major bacterial species implicated in chornic periodontitis, a disease characterized by inflammatory destruction of the tooth supporting tissues. Its main virulence factors are lipopolysaccharide (LPS) and gingipains, a group of cysteine proteinases. Interleukin (IL)-18 is a potent pro-inflammatory cytokine with structural similarities to IL-1β. This study aimed to investigate if P .gingivalis regulates IL-1β and IL-18 in monocytic cells. Monomac-6 cells were challenged with P. gingivalis culture supernatants. Quantitative real-time PCR and ELISA were used to investigate IL-1β and IL-18 mRNA expression and protein secretion, respectively. P. gingivalis enhanced IL-1β and IL-18 mRNA expression, the former being induced earlier, but transiently. IL-18 up-regulation was not affected by P. gingivalis heat-inactivation or chemical inhibition of its gingipains, whereas both treatments resulted in 50% reduction of IL-1β expression. Purified P. gingivalis LPS enhanced both IL-1β and IL-18 expression. However, only IL-1β, but not IL-18, secretion was detected, and was up-regulated by P. gingivalis. In conclusion, although IL-1β and IL-18 belong to the same cytokine family, their gene expression and secretion are differentially regulated in human monocytic cells in response to P. gingivalis. Therefore, cytokines of the IL-1 family may participate via different pathways in the complex pathogenesis of periodontitis.
KW - Interleukin-1β
KW - Interleukin-18
KW - Monocytes
KW - Periodontal disease
KW - Porphyromonas gingivalis
UR - http://www.scopus.com/inward/record.url?scp=59249098535&partnerID=8YFLogxK
U2 - 10.1016/j.cyto.2008.11.005
DO - 10.1016/j.cyto.2008.11.005
M3 - Article
C2 - 19091595
AN - SCOPUS:59249098535
SN - 1043-4666
VL - 45
SP - 99
EP - 104
JO - Cytokine
JF - Cytokine
IS - 2
ER -