Secretory leukocyte protease inhibitor regulates human periodontal ligament cell production of pro-inflammatory cytokines

Research output: Contribution to journalArticle


Objective: Regulation of immune-like cell properties of periodontal ligament (PDL) cells is not understood. We investigate the importance of secretory leukocyte protease inhibitor (SLPI) for production of pro-inflammatory cytokines in human PDL cells. Materials and methods: PDL cells were isolated from teeth extracted for orthodontic reasons. Cellular location of SLPI was investigated by immunocytochemistry. Cytokine transcript and protein expression were assessed by quantitative real-time RT-PCR and Western blotting. SLPI gene activity was knocked-down by siRNA. NF-κB signaling was assessed by measuring IκBα, and phosphorylated p65 and p105 protein expression. Results: PDL cells showed cytoplasmic expression of SLPI. Cellular expression level of SLPI negatively correlated to LPS-induced stimulation of IL-6 and MCP-1. Both SLPI gene activity and protein were reduced by about 70% in PDL cells treated with SLPI siRNA compared to cells treated with non-coding construct. Treatment with SLPI siRNA was associated with up-regulation of both basal and LPS-stimulated IL-6, MCP-1 and TLRs mRNA expression. The up-regulation of MCP-1 transcript in SLPI siRNA-treated cells was confirmed on protein level. SLPI siRNA-treatment enhanced the phosphorylated NF-κB p105 protein expression. Conclusions: SLPI regulates PDL cell pro-inflammatory cytokine expression and modulates NF-κB signaling, suggesting that SLPI governs the immune cell-like properties of PDL cells.


External organisations
  • Swedish Dental Service of Skåne
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Immunology in the medical area


  • Cytokines, NF-κB, Periodontal ligament cells, Periodontitis, Secretory leukocyte protease inhibitor
Original languageEnglish
Pages (from-to)823-831
JournalInflammation Research
Issue number9
Early online date2017 Jun 8
Publication statusPublished - 2017
Publication categoryResearch