Immortalized Human Gingival Keratinocytes-hTERT

Immortalized human gingival keratinocytes-hTERT are established by transducing primary human gingival keratinocytes with a lentiviral expression vector encoding the human telomerase reverse transcriptase (hTERT) gene. The advantages of hTERT-immortalized gingival keratinocytes are threefold. First, extended proliferative capacity – whereas primary cells senesce within a few passages, hTERT-transduced cells can be continuously cultured beyond 20 passages without growth retardation or replicative senescence. The telomerase immortalized gingival keratinocyte (TIGK) line has been reported to undergo 36 passages while maintaining robust proliferation. Second, phenotypic fidelity – immortalized cells retain morphological characteristics, karyotypic stability, proliferation rates, and cytokeratin expression profiles (including cytokeratins 2, 17 and 19) comparable to primary gingival keratinocytes. When cultured under stratifying conditions, they recapitulate suprabasal differentiation markers consistent with junctional epithelium. This preservation of lineage-specific traits distinguishes hTERT-immortalized lines from virally immortalized alternatives, which may exhibit chromosomal rearrangements or aberrant differentiation. Third, experimental reproducibility and scalability – the consistent growth and stable phenotype eliminate the donor-to-donor variability inherent to primary cultures, enabling repeated experiments and high-throughput screening. These cells are amenable to co-culture with fibroblasts for constructing three-dimensional gingival tissue equivalents and organotypic multilayered models, and have been successfully integrated into full-thickness reconstructed human gingiva for wound healing and toxicological studies. Collectively, hTERT-immortalized human gingival keratinocytes offer a robust, phenotypically faithful, and ethically sustainable in vitro model system that bridges the gap between primary cell biology and translational oral research.