The human periodontal ligament cell: a fibroblast-like cell acting as an immune cell.
BACKGROUND
Periodontal ligament cells are fibroblast-like cells characterized by collagen production but also possessing some osteoblastic features. In the light of numerous studies presented during recent times, which show that human periodontal ligament cells also produce cytokines and chemokines in response to inflammation promoters, it is reasonable to suggest that periodontal ligament cells play a role as promoters of periodontal inflammation through these mechanisms.


METHODS
The periodontal ligament, which harbours the periodontal ligament cells, is a part of the attachment apparatus comprised of periodontal ligament cells, extracellular matrix and fibres, attaching the root cement to the alveolar bone. Periodontal ligament cells are in close proximity to bacteria within the plaque and the pocket, and thus these cells are readily accessible to bacterial endotoxins and other promoters of inflammation.


RESULTS
Cytokines and chemokines, released by periodontal ligament cells upon stimulation with inflammation promoters, reach the blood vessels easily thanks to rich vascularization of the periodontium stimulating recruitment of white blood cells to the site of inflammation. In addition to classical inflammatory cells, such as leucocytes, macrophages and mast cells, the periodontal ligament cells also contribute to periodontal inflammation via their production and release of cytokines and chemokines.


CONCLUSIONS
Therefore, pharmacological treatment of periodontitis should aim to reduce the release of proinflammatory agents not only from classical inflammatory cells but also from periodontal ligament cells.
Department of Experimental Medical Science, Lund University, Lund, Sweden.
D
D
Jönsson
D
D
Nebel
G
G
Bratthall
B-O
BO
Nilsson
D001427:Bacterial Toxins / Q000276:immunology; D018925:Chemokines / Q000276:immunology; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D005347:Fibroblasts / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007107:Immune System / Q000166:cytology; D018836:Inflammation Mediators / Q000276:immunology; D010513:Periodontal Ligament / Q000166:cytology* / Q000276:immunology
D001427:Bacterial Toxins; D018925:Chemokines; D016207:Cytokines; D018836:Inflammation Mediators