Compromised inflammatory cytokine response to P. gingivalis LPS by fibroblasts from inflamed human gingiva

The aims of this study were to compare the in vitro cytokine response of gingival fibroblasts (GF's) from healthy and inflamed human gingival tissues and to assess whether GF's from inflamed gingivae are capable of mounting a secondary inflammatory response after exposure to P. gingivalis LPS.

GF's were obtained from healthy donors and periodontitis patients and cultured in vitro. Cells were exposed to P. gingivalis LPS for 24h before measurement of MCP-1, GRO, IL-6, IL-8 and VEGF using a bead-based multiplex assay. Statistical comparisons were made between LPS-exposed GF's and unstimulated cells as well as the two patient groups by two-way ANOVA.

GF's exposed to P. gingivalis LPS significantly increased their production of MCP-1, GRO, IL-6, IL-8 and VEGF compared to unstimulated cells. GF's isolated from inflamed tissue from periodontitis patients demonstrated consistently less cytokine production after exposure to P. gingivalis LPS, most notably for GRO and IL-6.

The current study demonstrates that GF's play an active role in the inflammatory response in periodontal disease by producing a number of chemokines and cytokines. Furthermore, inflamed GF's may be compromised in their ability to mount an adequate secondary immune response in relation to chemokine/cytokine production.

The compromised inflammatory cytokine response of inflamed human gingival fibroblasts to P. gingivalis LPS may impact on their ability to recruit and activate inflammatory cells while maintaining persistent inflammation, a key feature of periodontal disease.