Stomatology ›› 2026, Vol. 46 ›› Issue (7): 481-488.doi: 10.13591/j.cnki.kqyx.2026.07.001

• Basic and Clinical Research •     Next Articles

Filifactor alocis exacerbates experimental periodontitis by modulating CXCL3-mediated neutrophil infiltration

ZHANG Qunbo1,2,3, LI Cheng1,2,3, REN Minyi1,2,3, LI Lu1,2,3   

  1. 1 Department of Periodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China
  • Received:2026-01-09 Online:2026-07-28 Published:2026-07-23

Abstract:

Objective To investigate the molecular mechanism by which Filifactor alocis (F. alocis) regulates neutrophil infiltration and exacerbates experimental periodontitis. Methods A F. alocis infection model was established in neutrophils. Neutrophil cytotoxicity under F. alocis stimulation was assessed using CCK-8 assay. RT-qPCR was performed to detect the mRNA expression of neutrophil chemokines (C-X-C motif chemokine ligand 1 (CXCL1), CXCL2, CXCL3, CXCL5, CXCL6, CXCL8, CXCL16) and inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2). CXCL3 secretion levels were measured using ELISA. The expression of CXCL3 in neutrophils was detected by cellular immunofluorescence. Chemotaxis was measured using Transwell assays. A mouse model of F. alocis-induced periodontitis was established by silk ligation around bilateral maxillary second molars combined with oral smearing of F. alocis. CXCL3 neutralizing antibody was administered by gingival injection. Alveolar bone destruction was assessed using Micro-CT, and the infiltration of lymphocyte antigen 6 complex locus G (Ly-6G)-positive neutrophils in periodontal tissues was detected by tissue immunofluorescence staining. Results F. alocis exhibited minimal cytotoxic effects on neutrophils at a multiplicity of infection (MOI) of 10 within a 6-hour co-culture period. F. alocis upregulated the mRNA expression of CXCL2, CXCL3, CXCL8, TNF-α, IL-1β and IL-6, while downregulating CCL2 expression, thereby enhancing neutrophil chemotaxis and inflammatory cytokine release. In vivo, F. alocis aggravated alveolar bone destruction and neutrophil infiltration in the periodontal tissues of periodontitis model mice. Notably, administration of a CXCL3-neutralizing antibody effectively suppressed this inflammatory process. Conclusion F. alocis promotes neutrophil recruitment into periodontal tissues via CXCL3, exacerbating alveolar bone destruction and tissue inflammation in periodontitis. These findings identify CXCL3 as a key chemokine mediating F. alocis pathogenicity and a potential therapeutic target.

Key words: Filifactor alocis, neutrophils, periodontitis, C-X-C motif chemokine ligand 3 (CXCL3)

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