Antimicrobial activity and regulation of CXCL9 and CXCL10 in oral keratinocytes.
Chemokine (C-X-C motif) ligand (CXCL)9 and CXCL10 are dysregulated in oral inflammatory conditions, and it is not known if these chemokines target microorganisms that form oral biofilm. The aim of this study was to investigate the antimicrobial activity of CXCL9 and CXCL10 on oral microflora and their expression profiles in oral keratinocytes following exposure to inflammatory and infectious stimuli. Streptococcus sanguinis was used as a model and Escherichia coli as a positive control. The antimicrobial effect of CXCL9/CXCL10 was tested using a radial diffusion assay. mRNA transcripts were isolated from lipopolysaccharide (LPS)-treated and untreated (control) oral keratinocyte cell lines at 2-, 4-, 6-, and 8-h time-points of culture. The CXCL9/10 expression profile in the presence or absence of interferon-γ (IFN-γ) was assessed using semiquantitative PCR. Although both chemokines demonstrated antimicrobial activity, CXCL9 was the most effective chemokine against both S. sanguinis and E coli. mRNA for CXCL10 was expressed in control cells and its production was enhanced at all time-points following stimulation with LPS. Conversely, CXCL9 mRNA was not expressed in control or LPS-stimulated cells. Finally, stimulation with IFN-γ enhanced basal expression of both CXCL9 and CXCL10 in oral keratinocytes. Chemokines derived from oral epithelium, particularly CXCL9, demonstrate antimicrobial properties. Bacterial and inflammatory-stimulated up-regulation of CXCL9/10 could represent a key element in oral bacterial colonization homeostasis and host-defense mechanisms.
University College London, UCL Eastman Dental Institute, London, UK.
Alison
A
Marshall
University Federico II of Naples, Department of Neuroscience, Reproductive and Odontostomatological Sciences, Naples, Italy. antonio.celentano@unina.it.|The University of Melbourne, Melbourne Dental School and Oral Health CRC, Melbourne, Vic., Australia. antonio.celentano@unina.it.
Antonio
A
Celentano
The University of Melbourne, Melbourne Dental School and Oral Health CRC, Melbourne, Vic., Australia.
Nicola
N
Cirillo
University Federico II of Naples, Department of Neuroscience, Reproductive and Odontostomatological Sciences, Naples, Italy.
Michele D
MD
Mignogna
The University of Melbourne, Melbourne Dental School and Oral Health CRC, Melbourne, Vic., Australia.
Michael
M
McCullough
University College London, UCL Eastman Dental Institute, London, UK.
Stephen
S
Porter
D000890:Anti-Infective Agents; D054357:Chemokine CXCL10 / Q000502:physiology*; D054370:Chemokine CXCL9 / Q000502:physiology*; D004926:Escherichia coli; D006801:Humans; D007371:Interferon-gamma; D015603:Keratinocytes / Q000502:physiology*; D009055:Mouth / Q000382:microbiology; D013298:Streptococcus sanguis
D000890:Anti-Infective Agents; C114753:CXCL10 protein, human; C080810:CXCL9 protein, human; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; D007371:Interferon-gamma

Streptococcus sanguinis
; CCL28; CXCL10; CXCL9; chemokines