Establishment and characterization of a telomerase immortalized human gingival epithelial cell line

• Published in: Journal of periodontal research Vol. 48; no. 6; pp. 713 - 721
• Main Authors: Moffatt-Jauregui, C. E., Robinson, B., de Moya, A. V., Brockman, R. D., Roman, A. V., Cash, M. N., Culp, D. J., Lamont, R. J.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-12-2013
• Subjects: Adult; bmi1; Cell Count; Cell Culture Techniques; Cell Line, Transformed; Cell Proliferation; Cell Shape - physiology; Cellular Senescence - physiology; Dentistry; Epithelial Attachment - cytology; Epithelial Cells - cytology; Epithelial Cells - microbiology; Gingiva - cytology; Gingiva - microbiology; gingival epithelial cells; human telomerase reverse transcriptase; Humans; immortalization; Karyotype; Keratin-13 - metabolism; Keratin-14 - metabolism; Keratin-19 - metabolism; Microscopy, Confocal; Microscopy, Fluorescence; Polycomb Repressive Complex 1 - genetics; Porphyromonas gingivalis; Porphyromonas gingivalis - physiology; Retroviridae - genetics; telomerase; Telomerase - genetics; Telomere - physiology; Toll-Like Receptors - metabolism; Transduction, Genetic; Zinc Fingers - genetics; Porphyromonas gingivalis; gingival epithelial cells; telomerase; human telomerase reverse transcriptase; immortalization; bmi1
• ISSN: 0022-3484; 1600-0765
• DOI: 10.1111/jre.12059

Background and Objective
Gingival keratinocytes are used in model systems to investigate the interaction between periodontal bacteria and the epithelium in the initial stages of the periodontal disease process. Primary gingival epithelial cells (GECs) have a finite lifespan in culture before they enter senescence and cease to replicate, while epithelial cells immortalized with viral proteins can exhibit chromosomal rearrangements. The aim of this study was to generate a telomerase immortalized human gingival epithelial cell line and compare its in vitro behaviour to that of human GECs.
Material and Methods
Human primary GECs were immortalized with a bmi1/hTERT combination to prevent cell cycle triggers of senescence and telomere shortening. The resultant cell‐line, telomerase immortalized gingival keratinocytes (TIGKs), were compared to GECs for cell morphology, karyotype, growth and cytokeratin expression, and further characterized for replicative lifespan, expression of toll‐like receptors and invasion by P. gingivalis.
Results
TIGKs showed morphologies, karyotype, proliferation rates and expression of characteristic cytokeratin proteins comparable to GECs. TIGKs underwent 36 passages without signs of senescence and expressed transcripts for toll‐like receptors 1–6, 8 and 9. A subpopulation of cells underwent stratification after extended time in culture. The cytokeratin profiles of TIGK monolayers were consistent with basal cells. When allowed to stratify, cytokeratin profiles of TIGKs were consistent with suprabasal cells of the junctional epithelium. Further, TIGKs were comparable to GECs in previously reported levels and kinetics of invasion by wild‐type P. gingivalis and an invasion defective ΔserB mutant.
Conclusion
Results confirm bmi1/hTERT immortalization of primary GECs generated a robust cell line with similar characteristics to the parental cell type. TIGKs represent a valuable model system for the study of oral bacteria interactions with host gingival cells.