Interleukin-17 is disease promoting in early stages and protective in late stages of experimental periodontitis

PLoS One. 2022 Mar 17;17(3):e0265486. doi: 10.1371/journal.pone.0265486. eCollection 2022.

Abstract

Periodontitis is one of the most common infectious diseases in humans. It is characterized by a chronic inflammation of the tooth-supporting tissue that results in bone loss. However, the role and source of the pro-inflammatory cytokine interleukin-17 (IL-17) and of the cells producing it locally in the gingiva is still controversial. Th17 αβ T cells, CD4+ exFoxP3+ αβ T cells, or IL-17-producing γδ T cells (γδ17 cells) seem to be decisive cellular players in periodontal inflammation. To address these issues in an experimental model for periodontitis, we employed genetic mouse models deficient for either γδ T cells or IL-17 cytokines and assessed the bone loss during experimental periodontal inflammation by stereomicroscopic, histological, and μCT-analysis. Furthermore, we performed flow-cytometric analyses and qPCR-analyses of the gingival tissue. We found no γδ T cell- or IL-17-dependent change in bone loss after four weeks of periodontitis. Apart from that, our data are complementary with earlier studies, which suggested IL-17-dependent aggravation of bone loss in early periodontitis, but a rather bone-protective role for IL-17 in late stages of experimental periodontitis with respect to the osteoclastogenicity defined by the RANKL/OPG ratio.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alveolar Bone Loss* / pathology
  • Animals
  • Cytokines
  • Gingiva / pathology
  • Inflammation
  • Interleukin-17 / genetics
  • Mice
  • Periodontitis*

Substances

  • Cytokines
  • Interleukin-17

Grants and funding

This work was supported by the German–Israeli Foundation for Scientific Research and Development Grant 1432 (to A.-H.H. and I.P., http://www.gif.org.il/pages/default.aspx), by a grant from the Niedersächsisch-Israelische Forschungsförderung (to A.-H.H. and I.P.), and by the DG PARO CP GABA (to A.W., I.P., and M.S.) A. Wilharm and C. Binz were supported by the Hannover Biomedical Research School. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.