Establishment of gingival epithelial cell lines from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene

We established two gingival epithelial cell lines (GE1 and GE6), originatin g from transgenic mice harboring the temperature-sensitive simian virus 40 large T-antigen gene. GE1 and GE6 grew at a permissive temperature (33 degr eesC) in a pavement arrangement and solely formed multilayers that exhibite d morphological features similar to those of the stratified oral epithelium , with neither the use of stromal equivalents nor feeder layers. Both GE ce lls underwent apoptosis at a non-permissive temperature (39 degreesC). Char acteristic keratin peptides, keratin 4 and 13, for mucosal epithelium were obviously expressed in the suprabasal cells, and keratohyalin granules and involucrin were present in the surface flat cells in the multilayered cultu re. Keratin 10 (one of the markers for higher keratinized gingival epitheli um) was rarely found in some uppermost cells, and filaggrin (a component of keratohyalin granules) appeared sparsely in uppermost desquamating cells i n the older cultures. These observations indicated that GE1 and GE6 cells e xhibited the phenotype characterizing nonkeratinized sulcular epithelium, w hich possessed the potency undergoing keratinization in such highly stratif ied cultures as oral gingival epithelium. GE cells increased the expression levels of mRNA of interleukin-1 beta and tumor necrosis factor alpha by th e stimulation of lipopolysaccharide and extracellular substances of oral st reptococci. The GE cell lines thus could serve as an excellent experimental system for further studies on the physiology of gingival epithelium and co rresponding diseases, such as periodontal disease, epithelial hyperplasia, and gingival tumors.