Virulence of Filifactor alocis lipoteichoic acid on human gingival fibroblast

Abstract

ObjectivesThe purpose of this study was to investigate virulence of lipoteichoic acid extracted from Filifactor alocis (F. alocis) through comparison of previously known bacterial virulence factors. DesignF. alocis was cultured in columbia media including L-arginine and L-cysteine, and lipoteichoic acid (LTA) from F. alocis was purified using organic solvent and bead extraction. Human gingival fibroblasts (HGFs) were treated with the extracted LTA and other Gram-positive LTA or lipopolysaccharide of other periodontopathogens. The induction of cytokine expression was examined by real-time RT-PCR and ELISA, and the stimulated signaling pathway by the LTA was investigated by immunoblotting and various inhibitors. ResultsLTA induced expression of pro-inflammatory cytokines and Matrix-metalloprotein 2. Also, F. alocis LTA induced expression pro-inflammatory cytokines similar to Porphyromonas gingivalis lipopolysaccharide. The LTA activated NF-κB and MAP kinase pathway. Furthermore, the induction of TNF-α, IL-6, IL-8, and MMP-2 expression by F. alocis LTA was reduced by the inhibitor of NF-κB, ERK, JNK, and p38 pathway. ConclusionsLTA of F. alocis, a bacterium recently detected in periodontal patients, may play an important role in inducing periodontitis by induction of expression of pro-inflammatory cytokines